diff --git a/docs/Melon Developer Guide.txt b/docs/Melon Developer Guide.txt
index 5ac26768..be69eee9 100644
--- a/docs/Melon Developer Guide.txt	
+++ b/docs/Melon Developer Guide.txt	
@@ -2984,8 +2984,8 @@ Their definitions can be found in melon/include/mln_types.h.
          It will return the next timestamp depending on 'exp'. If failed, 0 will be returned.
 
   41) I/O Thread
-      a) int mln_iothread_init(mln_iothread_t *t, struct mln_iothread_attr *attr);
-         Initialize an iothread instance 't' with attribute 'attr'.
+      a) int mln_iothread_init(mln_iothread_t *t, mln_u32_t nthread, mln_iothread_entry_t entry, void *args, mln_iothread_msg_process_t handler);
+         Initialize an iothread instance 't' with attributes.
          Return value: 0 on success, otherwise -1.
 
       b) void mln_iothread_destroy(mln_iothread_t *t);
diff --git a/docs/book/cn/iothread.md b/docs/book/cn/iothread.md
index 76e8d7bc..d38d89c9 100644
--- a/docs/book/cn/iothread.md
+++ b/docs/book/cn/iothread.md
@@ -31,20 +31,18 @@ I/O线程算是一种另类线程池结构。但是这个组件主要用于图
 #### mln_iothread_init
 
 ```c
-int mln_iothread_init(mln_iothread_t *t, struct mln_iothread_attr *attr);
-
-struct mln_iothread_attr {
-    mln_u32_t                   nthread; //几个I/O线程
-    mln_iothread_entry_t        entry; //I/O线程入口函数
-    void                       *args; //I/O线程入口参数
-    mln_iothread_msg_process_t  handler; //消息处理函数
-};
+int mln_iothread_init(mln_iothread_t *t, mln_u32_t nthread, mln_iothread_entry_t entry, void *args, mln_iothread_msg_process_t handler);
 
 typedef void *(*mln_iothread_entry_t)(void *); //线程入口
 typedef void (*mln_iothread_msg_process_t)(mln_iothread_t *t, mln_iothread_ep_type_t from, mln_iothread_msg_t *msg);//消息处理函数
 ```
 
-描述：依据`attr`对`t`进行初始化。
+描述：依据`attr`对`t`进行初始化，参数：
+
+- `nthread` I/O线程数量
+- `entry` I/O线程入口函数
+- `args` I/O线程入口参数
+- `handler` 消息处理函数
 
 返回值：成功返回`0`，否则返回`-1`
 
@@ -181,13 +179,8 @@ int main(void)
 {
     int i, rc;
     mln_iothread_t t;
-    struct mln_iothread_attr tattr;
 
-    tattr.nthread = 1;
-    tattr.entry = (mln_iothread_entry_t)entry;
-    tattr.args = &t;
-    tattr.handler = (mln_iothread_msg_process_t)msg_handler;
-    if (mln_iothread_init(&t, &tattr) < 0) {
+    if (mln_iothread_init(&t, 1, (mln_iothread_entry_t)entry, &t, (mln_iothread_msg_process_t)msg_handler) < 0) {
         fprintf(stderr, "iothread init failed\n");
         return -1;
     }
diff --git a/docs/book/en/iothread.md b/docs/book/en/iothread.md
index 19c0efd7..0adbe47b 100644
--- a/docs/book/en/iothread.md
+++ b/docs/book/en/iothread.md
@@ -25,14 +25,7 @@ I/O thread is another kind of thread pool. But this component is mainly used for
 #### mln_iothread_init
 
 ```c
-int mln_iothread_init(mln_iothread_t *t, struct mln_iothread_attr *attr);
-
-struct mln_iothread_attr {
-    mln_u32_t                   nthread; //Total number of I/O threads
-    mln_iothread_entry_t        entry; //I/O thread entry function
-    void                       *args; //I/O thread entry parameters
-    mln_iothread_msg_process_t  handler; //message handler
-};
+int mln_iothread_init(mln_iothread_t *t, mln_u32_t nthread, mln_iothread_entry_t entry, void *args, mln_iothread_msg_process_t handler);
 
 typedef void *(*mln_iothread_entry_t)(void *); //I/O thread entry function
 typedef void (*mln_iothread_msg_process_t)(mln_iothread_t *t, mln_iothread_ep_type_t from, mln_iothread_msg_t *msg);//message handler
@@ -40,6 +33,11 @@ typedef void (*mln_iothread_msg_process_t)(mln_iothread_t *t, mln_iothread_ep_ty
 
 Description: Initialize `t` according to `attr`.
 
+- `nthread` Total number of I/O threads.
+- `entry` I/O thread entry function.
+- `args` I/O thread entry parameters.
+- `handler` message handler.
+
 Return value: return `0` on success, otherwise return `-1`
 
 
@@ -181,13 +179,8 @@ int main(void)
 {
     int i, rc;
     mln_iothread_t t;
-    struct mln_iothread_attr tattr;
 
-    tattr.nthread = 1;
-    tattr.entry = (mln_iothread_entry_t)entry;
-    tattr.args = &t;
-    tattr.handler = (mln_iothread_msg_process_t)msg_handler;
-    if (mln_iothread_init(&t, &tattr) < 0) {
+    if (mln_iothread_init(&t, 1, (mln_iothread_entry_t)entry, &t, (mln_iothread_msg_process_t)msg_handler) < 0) {
         fprintf(stderr, "iothread init failed\n");
         return -1;
     }
diff --git a/include/mln_iothread.h b/include/mln_iothread.h
index aeb62e31..cf71040e 100644
--- a/include/mln_iothread.h
+++ b/include/mln_iothread.h
@@ -30,13 +30,6 @@ struct mln_iothread_msg_s {
     pthread_mutex_t             mutex;
 };
 
-struct mln_iothread_attr {
-    mln_u32_t                   nthread;
-    mln_iothread_entry_t        entry;
-    void                       *args;
-    mln_iothread_msg_process_t  handler;
-};
-
 struct mln_iothread_s {
     pthread_mutex_t             io_lock;
     pthread_mutex_t             user_lock;
@@ -59,7 +52,7 @@ struct mln_iothread_s {
 #define mln_iothread_msg_type(m)       ((m)->type)
 #define mln_iothread_msg_data(m)       ((m)->data)
 
-extern int mln_iothread_init(mln_iothread_t *t, struct mln_iothread_attr *attr);
+extern int mln_iothread_init(mln_iothread_t *t, mln_u32_t nthread, mln_iothread_entry_t entry, void *args, mln_iothread_msg_process_t handler);
 extern void mln_iothread_destroy(mln_iothread_t *t);
 extern int mln_iothread_send(mln_iothread_t *t, mln_u32_t type, void *data, mln_iothread_ep_type_t to, mln_u32_t feedback);
 extern int mln_iothread_recv(mln_iothread_t *t, mln_iothread_ep_type_t from);
diff --git a/src/mln_iothread.c b/src/mln_iothread.c
index 36631d9c..5c3b3ee3 100644
--- a/src/mln_iothread.c
+++ b/src/mln_iothread.c
@@ -23,12 +23,13 @@ MLN_CHAIN_FUNC_DECLARE(mln_iothread_msg, mln_iothread_msg_t, static inline void,
 MLN_CHAIN_FUNC_DEFINE(mln_iothread_msg, mln_iothread_msg_t, static inline void, prev, next);
 
 MLN_FUNC(, int, mln_iothread_init, \
-         (mln_iothread_t *t, struct mln_iothread_attr *attr), (t, attr), \
+         (mln_iothread_t *t, mln_u32_t nthread, mln_iothread_entry_t entry, void *args, mln_iothread_msg_process_t handler), \
+         (t, nthread, entry, args, handler), \
 {
     mln_u32_t i;
     int fds[2];
 
-    if (!attr->nthread || attr->entry == NULL) {
+    if (!nthread || entry == NULL) {
         return -1;
     }
 
@@ -39,14 +40,14 @@ MLN_FUNC(, int, mln_iothread_init, \
     t->user_fd = fds[1];
     mln_iothread_fd_nonblock_set(t->io_fd);
     mln_iothread_fd_nonblock_set(t->user_fd);
-    t->entry = attr->entry;
-    t->args = attr->args;
-    t->handler = attr->handler;
+    t->entry = entry;
+    t->args = args;
+    t->handler = handler;
     pthread_mutex_init(&(t->io_lock), NULL);
     pthread_mutex_init(&(t->user_lock), NULL);
     t->io_head = t->io_tail = NULL;
     t->user_head = t->user_tail = NULL;
-    t->nthread = attr->nthread;
+    t->nthread = nthread;
 
     if ((t->tids = (pthread_t *)calloc(t->nthread, sizeof(pthread_t))) == NULL) {
         mln_socket_close(fds[0]);