diff --git a/os/src/syscall/mod.rs b/os/src/syscall/mod.rs
index 3b579ba64..9df8024c0 100644
--- a/os/src/syscall/mod.rs
+++ b/os/src/syscall/mod.rs
@@ -10,6 +10,8 @@
 //! `sys_` then the name of the syscall. You can find functions like this in
 //! submodules, and you should also implement syscalls this way.
 
+use crate::task::TASK_MANAGER;
+
 /// write syscall
 const SYSCALL_WRITE: usize = 64;
 /// exit syscall
@@ -29,6 +31,7 @@ use process::*;
 
 /// handle syscall exception with `syscall_id` and other arguments
 pub fn syscall(syscall_id: usize, args: [usize; 3]) -> isize {
+    TASK_MANAGER.add_syscall_times(syscall_id);
     match syscall_id {
         SYSCALL_WRITE => sys_write(args[0], args[1] as *const u8, args[2]),
         SYSCALL_EXIT => sys_exit(args[0] as i32),
diff --git a/os/src/syscall/process.rs b/os/src/syscall/process.rs
index ab43bbe7d..8dd37fb11 100644
--- a/os/src/syscall/process.rs
+++ b/os/src/syscall/process.rs
@@ -1,6 +1,6 @@
 //! Process management syscalls
 use crate::{
-    task::{exit_current_and_run_next, suspend_current_and_run_next},
+    task::{exit_current_and_run_next, suspend_current_and_run_next, find_syscall_times},
     timer::get_time_us,
 };
 
@@ -38,8 +38,28 @@ pub fn sys_get_time(ts: *mut TimeVal, _tz: usize) -> isize {
     0
 }
 
-// TODO: implement the syscall
+/// get the information of syscall and do some change
 pub fn sys_trace(_trace_request: usize, _id: usize, _data: usize) -> isize {
     trace!("kernel: sys_trace");
-    -1
+    match _trace_request {
+        0 => {
+            let ptr = _id as *const u8;
+            unsafe {
+                *ptr as isize
+            }
+        },
+        1 => {
+            let ptr = _id as *mut u8;
+            unsafe {
+                *ptr = (_data & 0xFF) as u8;
+            }
+            0
+        },
+        2 => {
+            find_syscall_times(_id) as isize
+        },
+        _ => {
+            -1
+        }
+    }
 }
diff --git a/os/src/task/mod.rs b/os/src/task/mod.rs
index c1636ef47..1c90cda28 100644
--- a/os/src/task/mod.rs
+++ b/os/src/task/mod.rs
@@ -54,6 +54,7 @@ lazy_static! {
         let mut tasks = [TaskControlBlock {
             task_cx: TaskContext::zero_init(),
             task_status: TaskStatus::UnInit,
+            syscall_counts: [0; 500],
         }; MAX_APP_NUM];
         for (i, task) in tasks.iter_mut().enumerate() {
             task.task_cx = TaskContext::goto_restore(init_app_cx(i));
@@ -135,6 +136,20 @@ impl TaskManager {
             panic!("All applications completed!");
         }
     }
+    
+    /// Get the syscall times
+    fn find_syscall_times(&self, _id: usize) -> usize{
+        let inner = self.inner.exclusive_access();
+        let current = inner.current_task;
+        inner.tasks[current].syscall_counts[_id]
+    }
+    
+    /// Add the syscall times
+    pub fn add_syscall_times(&self, _id: usize) {
+        let mut inner = TASK_MANAGER.inner.exclusive_access();
+        let current = inner.current_task;
+        inner.tasks[current].syscall_counts[_id] += 1;
+    }
 }
 
 /// Run the first task in task list.
@@ -169,3 +184,8 @@ pub fn exit_current_and_run_next() {
     mark_current_exited();
     run_next_task();
 }
+
+/// Return the given id syscall times
+pub fn find_syscall_times(_id: usize) -> usize {
+    TASK_MANAGER.find_syscall_times(_id)
+}
diff --git a/os/src/task/switch.rs b/os/src/task/switch.rs
index 3535a5ca6..0ca59590d 100644
--- a/os/src/task/switch.rs
+++ b/os/src/task/switch.rs
@@ -13,5 +13,8 @@ global_asm!(include_str!("switch.S"));
 extern "C" {
     /// Switch to the context of `next_task_cx_ptr`, saving the current context
     /// in `current_task_cx_ptr`.
-    pub fn __switch(current_task_cx_ptr: *mut TaskContext, next_task_cx_ptr: *const TaskContext);
+    pub fn __switch(
+        current_task_cx_ptr: *mut TaskContext,
+        next_task_cx_ptr: *const TaskContext
+    );
 }
diff --git a/os/src/task/task.rs b/os/src/task/task.rs
index e6580c9a9..b3ef6f125 100644
--- a/os/src/task/task.rs
+++ b/os/src/task/task.rs
@@ -9,6 +9,8 @@ pub struct TaskControlBlock {
     pub task_status: TaskStatus,
     /// The task context
     pub task_cx: TaskContext,
+    /// The task mask
+    pub syscall_counts: [usize; 500],
 }
 
 /// The status of a task