diff --git a/Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.c b/Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.c
index 8bdf03709..403d16e61 100644
--- a/Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.c
+++ b/Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.c
@@ -153,4 +153,9 @@ bool semaphore_wait(int sem_id)
 bool semaphore_signal(int sem_id)
 {
     return syscall(SYSCALL_SEMAPHORE, (intptr_t)SYS_SEM_SIGNAL, (intptr_t)sem_id, 0, 0);
+}
+
+int sleep(intptr_t ms)
+{
+    return syscall(SYSCALL_SLEEP, (intptr_t)ms, 0, 0, 0);
 }
\ No newline at end of file
diff --git a/Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.h b/Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.h
index e76f684a1..de683f9cd 100644
--- a/Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.h
+++ b/Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.h
@@ -34,6 +34,7 @@
 #define SYSCALL_KILL            12  // kill the task by id
 
 #define SYSCALL_SEMAPHORE       13  // semaphore related operations
+#define SYSCALL_SLEEP           14  // sleep
 // clang-format on
 
 typedef enum {
@@ -105,4 +106,6 @@ uintptr_t get_tick();
 int semaphore_new(int val);
 bool semaphore_free(int sem_id);
 bool semaphore_wait(int sem_id);
-bool semaphore_signal(int sem_id);
\ No newline at end of file
+bool semaphore_signal(int sem_id);
+
+int sleep(intptr_t ms);
\ No newline at end of file
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/include/syscall.h b/Ubiquitous/XiZi_AIoT/softkernel/include/syscall.h
index 14e2ddc7e..f2c0265d4 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/include/syscall.h
+++ b/Ubiquitous/XiZi_AIoT/softkernel/include/syscall.h
@@ -48,6 +48,7 @@ Modification:
 #define SYSCALL_KILL            12  // kill the task by id
 
 #define SYSCALL_SEMAPHORE       13  // semaphore related operations
+#define SYSCALL_SLEEP           14  // sleep
 // clang-format on
 
 #ifndef __ASSEMBLER__
@@ -113,4 +114,5 @@ int sys_unbind_irq_all(struct Thread* task);
 int sys_unbind_irq(struct Thread* task, int irq_num);
 
 int sys_semaphore(sys_sem_option op, int sem_id);
+int sys_sleep(intptr_t ms);
 #endif
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/include/task.h b/Ubiquitous/XiZi_AIoT/softkernel/include/task.h
index accfb513a..096a0613e 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/include/task.h
+++ b/Ubiquitous/XiZi_AIoT/softkernel/include/task.h
@@ -44,6 +44,7 @@ Modification:
 #define TASK_MAX_PRIORITY 32
 #define TASK_DEFAULT_PRIORITY 2
 #define TASK_NAME_MAX_LEN 16
+#define SLEEP_MONITOR_CORE 0
 
 enum ProcState {
     INIT = 0,
@@ -51,6 +52,7 @@ enum ProcState {
     RUNNING,
     DEAD,
     BLOCKED,
+    SLEEPING,
     NEVER_RUN,
 };
 
@@ -72,6 +74,10 @@ struct ThreadContext {
     struct trapframe* trapframe;
 };
 
+struct TaskSleepContext {
+    int64_t remain_ms;
+};
+
 /* Process Control Block */
 struct Thread {
     /* task name */
@@ -97,6 +103,7 @@ struct Thread {
 
     /* task schedule attributes */
     struct double_list_node node;
+    struct TaskSleepContext sleep_context;
     enum ProcState state;
     int priority; // priority
     int remain_tick;
@@ -114,6 +121,7 @@ struct XiziTaskManager {
     struct double_list_node task_list_head[TASK_MAX_PRIORITY]; /* list of task control blocks that are allocated */
     struct double_list_node task_running_list_head;
     struct double_list_node task_blocked_list_head;
+    struct double_list_node task_sleep_list_head;
     struct XiziSemaphorePool semaphore_pool;
 
     /* mem allocator */
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/Makefile b/Ubiquitous/XiZi_AIoT/softkernel/syscall/Makefile
index 4adbb947d..6a144502d 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/Makefile
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/Makefile
@@ -1,6 +1,7 @@
 SRC_FILES := syscall.c \
 	sys_spawn.c \
 	sys_thread.c \
+	sys_sleep.c \
 	sys_yield.c \
 	sys_register_as_server.c \
 	sys_connect_session.c \
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_state.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_state.c
index 67aea6b05..53406e3e2 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_state.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_state.c
@@ -91,6 +91,12 @@ void show_tasks(void)
         SHOWTASK_TASK_BASE_INFO(task);
     }
 
+    DOUBLE_LIST_FOR_EACH_ENTRY(task, &xizi_task_manager.task_sleep_list_head, node)
+    {
+        LOG_PRINTF("%-8s", "SLEEP");
+        SHOWTASK_TASK_BASE_INFO(task);
+    }
+
     struct ksemaphore* sem = NULL;
     DOUBLE_LIST_FOR_EACH_ENTRY(sem, &xizi_task_manager.semaphore_pool.sem_list_guard, sem_list_node)
     {
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/syscall.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/syscall.c
index d3ae51f67..c6985c194 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/syscall.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/syscall.c
@@ -80,6 +80,9 @@ int syscall(int sys_num, uintptr_t param1, uintptr_t param2, uintptr_t param3, u
     case SYSCALL_SEMAPHORE:
         ret = sys_semaphore((sys_sem_option)param1, (int)param2);
         break;
+    case SYSCALL_SLEEP:
+        ret = sys_sleep((intptr_t)param1);
+        break;
     default:
         ERROR("Unsurport syscall(%d) right now\n", sys_num);
         ret = -1;
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/task/task.c b/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
index 27df0e16e..9b9a90ede 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
@@ -38,6 +38,7 @@ Modification:
 #include "scheduler.h"
 #include "syscall.h"
 #include "task.h"
+#include "trap_common.h"
 
 struct CPU global_cpus[NR_CPU];
 uint32_t ready_task_priority;
@@ -70,6 +71,7 @@ static void _task_manager_init()
     }
     doubleListNodeInit(&xizi_task_manager.task_blocked_list_head);
     doubleListNodeInit(&xizi_task_manager.task_running_list_head);
+    doubleListNodeInit(&xizi_task_manager.task_sleep_list_head);
     // init task (slab) allocator
     slab_init(&xizi_task_manager.memspace_allocator, sizeof(struct MemSpace));
     slab_init(&xizi_task_manager.task_allocator, sizeof(struct Thread));
@@ -286,6 +288,7 @@ extern void context_switch(struct context**, struct context*);
 static void _scheduler(struct SchedulerRightGroup right_group)
 {
     struct MmuCommonDone* p_mmu_driver = AchieveResource(&right_group.mmu_driver_tag);
+//    struct XiziTrapDriver* p_intr_driver = AchieveResource(&right_group.intr_driver_tag);
     struct Thread* next_task;
     struct CPU* cpu = cur_cpu();
 
@@ -347,7 +350,7 @@ static void _task_block(struct double_list_node* head, struct Thread* task)
 static void _task_unblock(struct Thread* task)
 {
     assert(task != NULL);
-    assert(task->state == BLOCKED);
+    assert(task->state == BLOCKED || task->state == SLEEPING);
     task_node_leave_list(task);
     task->state = READY;
     task_node_add_to_ready_list_back(task);
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/trap/clock_irq_handler.c b/Ubiquitous/XiZi_AIoT/softkernel/trap/clock_irq_handler.c
index eba875e07..937e4b219 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/trap/clock_irq_handler.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/trap/clock_irq_handler.c
@@ -69,6 +69,8 @@ int xizi_clock_handler(int irq, void* tf, void* arg)
     if (p_clock_driver->is_timer_expired()) {
         p_clock_driver->clear_clock_intr();
         global_tick++;
+
+        // handle current thread
         struct Thread* current_task = cur_cpu()->task;
         if (current_task) {
             current_task->remain_tick--;
@@ -77,6 +79,18 @@ int xizi_clock_handler(int irq, void* tf, void* arg)
                 xizi_task_manager.task_yield_noschedule(current_task, false);
             }
         }
+
+        // todo: cpu 0 will handle sleeping thread
+        struct Thread* thread = NULL;
+        DOUBLE_LIST_FOR_EACH_ENTRY(thread, &xizi_task_manager.task_sleep_list_head, node)
+        {
+            assert(thread->state == SLEEPING);
+            thread->sleep_context.remain_ms--;
+            if (thread->sleep_context.remain_ms <= 0) {
+                xizi_task_manager.task_unblock(thread);
+                break;
+            }
+        }
     }
     return 0;
 }
\ No newline at end of file