diff --git a/src/libos/src/fs/hostfs.rs b/src/libos/src/fs/hostfs.rs
new file mode 100644
index 00000000..37b7f154
--- /dev/null
+++ b/src/libos/src/fs/hostfs.rs
@@ -0,0 +1,283 @@
+use alloc::string::String;
+use alloc::sync::{Arc, Weak};
+use core::any::Any;
+use rcore_fs::vfs::*;
+use std::io::{Read, Seek, SeekFrom, Write};
+use std::path::{Path, PathBuf};
+use std::sync::{SgxMutex as Mutex, SgxMutexGuard as MutexGuard};
+use std::untrusted::fs;
+use std::untrusted::path::PathEx;
+
+/// Untrusted file system at host
+pub struct HostFS {
+    path: PathBuf,
+    self_ref: Weak<HostFS>,
+}
+
+/// INode for `HostFS`
+pub struct HNode {
+    path: PathBuf,
+    file: Mutex<Option<fs::File>>,
+    fs: Arc<HostFS>,
+}
+
+impl FileSystem for HostFS {
+    fn sync(&self) -> Result<()> {
+        unimplemented!()
+    }
+
+    fn root_inode(&self) -> Arc<INode> {
+        Arc::new(HNode {
+            path: self.path.clone(),
+            file: Mutex::new(None),
+            fs: self.self_ref.upgrade().unwrap(),
+        })
+    }
+
+    fn info(&self) -> FsInfo {
+        unimplemented!()
+    }
+}
+
+impl HostFS {
+    /// Create a new `HostFS` from host `path`
+    pub fn new(path: impl AsRef<Path>) -> Arc<HostFS> {
+        HostFS {
+            path: path.as_ref().to_path_buf(),
+            self_ref: Weak::default(),
+        }
+        .wrap()
+    }
+
+    /// Wrap pure `HostFS` with Arc
+    /// Used in constructors
+    fn wrap(self) -> Arc<Self> {
+        // Create an Arc, make a Weak from it, then put it into the struct.
+        // It's a little tricky.
+        let fs = Arc::new(self);
+        let weak = Arc::downgrade(&fs);
+        let ptr = Arc::into_raw(fs) as *mut Self;
+        unsafe {
+            (*ptr).self_ref = weak;
+        }
+        unsafe { Arc::from_raw(ptr) }
+    }
+}
+
+// workaround for unable to `impl From<std::io::Error> for FsError`
+macro_rules! try_std {
+    ($ret: expr) => {
+        $ret.map_err(|e| e.into_fs_error())?
+    };
+}
+
+impl INode for HNode {
+    fn read_at(&self, offset: usize, buf: &mut [u8]) -> Result<usize> {
+        let mut guard = self.open_file()?;
+        let file = guard.as_mut().unwrap();
+        try_std!(file.seek(SeekFrom::Start(offset as u64)));
+        let len = try_std!(file.read(buf));
+        Ok(len)
+    }
+
+    fn write_at(&self, offset: usize, buf: &[u8]) -> Result<usize> {
+        let mut guard = self.open_file()?;
+        let file = guard.as_mut().unwrap();
+        try_std!(file.seek(SeekFrom::Start(offset as u64)));
+        let len = try_std!(file.write(buf));
+        Ok(len)
+    }
+
+    fn poll(&self) -> Result<PollStatus> {
+        unimplemented!()
+    }
+
+    fn metadata(&self) -> Result<Metadata> {
+        let metadata = try_std!(self.path.metadata());
+        Ok(metadata.into_fs_metadata())
+    }
+
+    fn set_metadata(&self, metadata: &Metadata) -> Result<()> {
+        unimplemented!()
+    }
+
+    fn sync_all(&self) -> Result<()> {
+        unimplemented!()
+    }
+
+    fn sync_data(&self) -> Result<()> {
+        unimplemented!()
+    }
+
+    fn resize(&self, len: usize) -> Result<()> {
+        unimplemented!()
+    }
+
+    fn create(&self, name: &str, type_: FileType, mode: u32) -> Result<Arc<dyn INode>> {
+        let new_path = self.path.join(name);
+        if new_path.exists() {
+            return Err(FsError::EntryExist);
+        }
+        match type_ {
+            FileType::File => {
+                try_std!(fs::File::create(&new_path));
+            }
+            _ => unimplemented!("only support creating files in HostFS"),
+        }
+        Ok(Arc::new(HNode {
+            path: new_path,
+            file: Mutex::new(None),
+            fs: self.fs.clone(),
+        }))
+    }
+
+    fn link(&self, name: &str, other: &Arc<INode>) -> Result<()> {
+        let other = other.downcast_ref::<Self>().ok_or(FsError::NotSameFs)?;
+        try_std!(fs::hard_link(&other.path, &self.path.join(name)));
+        Ok(())
+    }
+
+    fn unlink(&self, name: &str) -> Result<()> {
+        let new_path = self.path.join(name);
+        if new_path.is_file() {
+            try_std!(fs::remove_file(new_path));
+        } else if new_path.is_dir() {
+            unimplemented!("no remove_dir in sgx_std?")
+        // fs::remove_dir(new_path)?;
+        } else {
+            return Err(FsError::EntryNotFound);
+        }
+        Ok(())
+    }
+
+    fn move_(&self, old_name: &str, target: &Arc<INode>, new_name: &str) -> Result<()> {
+        unimplemented!()
+    }
+
+    fn find(&self, name: &str) -> Result<Arc<INode>> {
+        let new_path = self.path.join(name);
+        if !new_path.exists() {
+            return Err(FsError::EntryNotFound);
+        }
+        Ok(Arc::new(HNode {
+            path: new_path,
+            file: Mutex::new(None),
+            fs: self.fs.clone(),
+        }))
+    }
+
+    fn get_entry(&self, id: usize) -> Result<String> {
+        if !self.path.is_dir() {
+            return Err(FsError::NotDir);
+        }
+        unimplemented!("no read_dir in sgx_std?")
+        // FIXME: read_dir
+
+        // self.path
+        //     .read_dir()
+        //     .map_err(|_| FsError::NotDir)?
+        //     .nth(id)
+        //     .map_err(|_| FsError::EntryNotFound)?
+        //     .file_name()
+        //     .into_string()
+        //     .map_err(|_| FsError::InvalidParam)
+    }
+
+    fn io_control(&self, cmd: u32, data: usize) -> Result<()> {
+        unimplemented!()
+    }
+
+    fn fs(&self) -> Arc<FileSystem> {
+        self.fs.clone()
+    }
+
+    fn as_any_ref(&self) -> &Any {
+        self
+    }
+}
+
+impl HNode {
+    /// Ensure to open the file and store a `File` into `self.file`,
+    /// return the `MutexGuard`.
+    /// If the type of `self.path` is not file, then return Err
+    fn open_file(&self) -> Result<MutexGuard<Option<fs::File>>> {
+        if !self.path.exists() {
+            return Err(FsError::EntryNotFound);
+        }
+        if !self.path.is_file() {
+            return Err(FsError::NotFile);
+        }
+        let mut maybe_file = self.file.lock().unwrap();
+        if maybe_file.is_none() {
+            let file = try_std!(fs::OpenOptions::new()
+                .read(true)
+                .write(true)
+                .create(true)
+                .open(&self.path));
+            *maybe_file = Some(file);
+        }
+        Ok(maybe_file)
+    }
+}
+
+trait IntoFsError {
+    fn into_fs_error(self) -> FsError;
+}
+
+impl IntoFsError for std::io::Error {
+    fn into_fs_error(self) -> FsError {
+        use std::io::ErrorKind;
+        match self.kind() {
+            ErrorKind::NotFound => FsError::EntryNotFound,
+            ErrorKind::AlreadyExists => FsError::EntryExist,
+            ErrorKind::WouldBlock => FsError::Again,
+            ErrorKind::InvalidInput => FsError::InvalidParam,
+            ErrorKind::InvalidData => FsError::InvalidParam,
+            _ => FsError::NotSupported,
+        }
+    }
+}
+
+trait IntoFsMetadata {
+    fn into_fs_metadata(self) -> Metadata;
+}
+
+impl IntoFsMetadata for fs::Metadata {
+    fn into_fs_metadata(self) -> Metadata {
+        use libc;
+        use std::os::fs::MetadataExt;
+        Metadata {
+            dev: self.st_dev() as usize,
+            inode: self.st_ino() as usize,
+            size: self.st_size() as usize,
+            blk_size: self.st_blksize() as usize,
+            blocks: self.st_blocks() as usize,
+            atime: Timespec {
+                sec: self.st_atime(),
+                nsec: self.st_atime_nsec() as i32,
+            },
+            mtime: Timespec {
+                sec: self.st_mtime(),
+                nsec: self.st_mtime_nsec() as i32,
+            },
+            ctime: Timespec {
+                sec: self.st_ctime(),
+                nsec: self.st_ctime_nsec() as i32,
+            },
+            type_: match self.st_mode() & 0xf000 {
+                libc::S_IFCHR => FileType::CharDevice,
+                libc::S_IFBLK => FileType::BlockDevice,
+                libc::S_IFDIR => FileType::Dir,
+                libc::S_IFREG => FileType::File,
+                libc::S_IFLNK => FileType::SymLink,
+                libc::S_IFSOCK => FileType::Socket,
+                _ => unimplemented!("unknown file type"),
+            },
+            mode: self.st_mode() as u16 & 0o777,
+            nlinks: self.st_nlink() as usize,
+            uid: self.st_uid() as usize,
+            gid: self.st_gid() as usize,
+            rdev: self.st_rdev() as usize,
+        }
+    }
+}
diff --git a/src/libos/src/fs/inode_file.rs b/src/libos/src/fs/inode_file.rs
index 60414c88..765921fe 100644
--- a/src/libos/src/fs/inode_file.rs
+++ b/src/libos/src/fs/inode_file.rs
@@ -1,9 +1,10 @@
 use rcore_fs::vfs::{FileSystem, FsError, INode};
-use rcore_fs_sefs::SEFS;
-use rcore_fs_ramfs::RamFS;
 use rcore_fs_mountfs::MountFS;
+use rcore_fs_ramfs::RamFS;
+use rcore_fs_sefs::SEFS;
 use std::fmt;
 
+use super::hostfs::HostFS;
 use super::sgx_impl::SgxStorage;
 use super::*;
 
@@ -13,8 +14,6 @@ lazy_static! {
         // ramfs as rootfs
         let rootfs = MountFS::new(RamFS::new());
         let root = rootfs.root_inode();
-        let bin = root.create("test", FileType::Dir, 0o777)
-            .expect("failed to mkdir: /test");
 
         // sefs
         let device = Box::new(SgxStorage::new("sefs"));
@@ -22,9 +21,20 @@ lazy_static! {
             .expect("failed to open SEFS");
 
         // mount sefs at /test
+        let bin = root.create("test", FileType::Dir, 0o777)
+            .expect("failed to mkdir: /test");
         bin.mount(sefs)
             .expect("failed to mount SEFS");
 
+        // HostFS
+        let hostfs = HostFS::new(".");
+
+        // mount HostFS at /host
+        let host = root.create("host", FileType::Dir, 0o777)
+            .expect("failed to mkdir: /host");
+        host.mount(hostfs)
+            .expect("failed to mount HostFS");
+
         root
     };
 }
diff --git a/src/libos/src/fs/mod.rs b/src/libos/src/fs/mod.rs
index 560554a1..c42df998 100644
--- a/src/libos/src/fs/mod.rs
+++ b/src/libos/src/fs/mod.rs
@@ -22,6 +22,7 @@ use std::mem::uninitialized;
 mod access;
 mod file;
 mod file_table;
+mod hostfs;
 mod inode_file;
 mod io_multiplexing;
 mod null;
diff --git a/test/Makefile b/test/Makefile
index 7023b082..857acef2 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -4,7 +4,7 @@ PROJECT_DIR := $(realpath $(CUR_DIR)/../)
 # Dependencies: need to be compiled but not to run by any Makefile target
 TEST_DEPS := dev_null
 # Tests: need to be compiled and run by test-% target
-TESTS := empty argv hello_world malloc mmap file getpid spawn pipe time truncate readdir mkdir link tls pthread uname rlimit client server server_epoll unix_socket cout cpuid rdtsc
+TESTS := empty argv hello_world malloc mmap file getpid spawn pipe time truncate readdir mkdir link tls pthread uname rlimit client server server_epoll unix_socket cout hostfs cpuid rdtsc
 # Benchmarks: need to be compiled and run by bench-% target
 BENCHES := spawn_and_exit_latency pipe_throughput unix_socket_throughput
 
diff --git a/test/hostfs/Makefile b/test/hostfs/Makefile
new file mode 100644
index 00000000..9e1b6dec
--- /dev/null
+++ b/test/hostfs/Makefile
@@ -0,0 +1,5 @@
+include ../test_common.mk
+
+EXTRA_C_FLAGS :=
+EXTRA_LINK_FLAGS :=
+BIN_ARGS :=
diff --git a/test/hostfs/main.c b/test/hostfs/main.c
new file mode 100644
index 00000000..3ce7c9f1
--- /dev/null
+++ b/test/hostfs/main.c
@@ -0,0 +1,43 @@
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+
+int main(int argc, const char* argv[]) {
+    int fd, len;
+    char read_buf[128] = {0};
+
+    // read
+    if ((fd = open("/host/hostfs/sample.txt", O_RDONLY)) < 0) {
+        printf("ERROR: failed to open a file for read\n");
+        return -1;
+    }
+    if ((len = read(fd, read_buf, sizeof(read_buf) - 1)) <= 0) {
+        printf("ERROR: failed to read from the file\n");
+        return -1;
+    }
+    close(fd);
+
+    if (strcmp("HostFS works!", read_buf) != 0) {
+        printf("ERROR: the message read from the file is not expected\n");
+        return -1;
+    }
+    printf("Read file from hostfs successfully!\n");
+
+    // write
+    if ((fd = open("/host/hostfs/test_write.txt", O_WRONLY | O_CREAT)) < 0) {
+        printf("ERROR: failed to open a file for write\n");
+        return -1;
+    }
+    const char WRITE_STR[] = "Write to hostfs successfully!";
+    if ((len = write(fd, WRITE_STR, sizeof(WRITE_STR))) <= 0) {
+        printf("ERROR: failed to write to the file\n");
+        return -1;
+    }
+    close(fd);
+
+    printf("Write file to hostfs finished. Please check its content.\n");
+    return 0;
+}
diff --git a/test/hostfs/sample.txt b/test/hostfs/sample.txt
new file mode 100644
index 00000000..750bc261
--- /dev/null
+++ b/test/hostfs/sample.txt
@@ -0,0 +1 @@
+HostFS works!
\ No newline at end of file