diff --git a/base/buffer.c b/base/buffer.c
index aecf87b..9f622a0 100644
--- a/base/buffer.c
+++ b/base/buffer.c
@@ -152,7 +152,7 @@ ssize_t buffer_read_fd(buffer *b, int fd, int *saved_errno)
     if (n == -1) {
        *saved_errno = errno;
     }
-    else if (n <= writable) {
+    else if (n <= (int)writable) {
         b->write_index += n;
     }
     else {
diff --git a/base/log.c b/base/log.c
index 9d0919d..1345dcf 100644
--- a/base/log.c
+++ b/base/log.c
@@ -8,7 +8,7 @@
 
 #define MAXLINE     256
 
-const static char *log_level_str[] = {
+static const char *log_level_str[] = {
         "[DEBUG]",
         "[INFO] ",
         "[WARN] ",
diff --git a/base/palloc.c b/base/palloc.c
index e3b1429..07dead2 100644
--- a/base/palloc.c
+++ b/base/palloc.c
@@ -50,7 +50,7 @@ void *palloc(mem_pool *pool, size_t size)
         /* 对齐指针 */
         last = align_ptr(p->last, MEM_POOL_ALIGNMENT);
 
-        if (p->end - last >= size) {
+        if ((size_t)(p->end - last) >= size) {
             p->last = last + size;
             return last;
         }
diff --git a/config.c b/config.c
index d8ae62f..5095228 100644
--- a/config.c
+++ b/config.c
@@ -147,6 +147,8 @@ void config(const char *path)
 
 static const char *config_main(const char *s, void *d)
 {
+    (void)d;
+
     conf_block *b = conf_main_block;
 
     s = first_not_space(s);
@@ -169,6 +171,8 @@ static const char *config_main(const char *s, void *d)
 
 static const char *config_events(const char *s, void *d)
 {
+    (void)d;
+
     conf_block *b = conf_events_block;
 
     s = expect(s, '{');
@@ -192,6 +196,8 @@ static const char *config_events(const char *s, void *d)
 
 static const char *config_server(const char *s, void *d)
 {
+    (void)d;
+
     conf_block *b = conf_server_block;
 
     s = expect(s, '{');
@@ -215,6 +221,8 @@ static const char *config_server(const char *s, void *d)
 
 static const char *config_location(const char *s, void *d)
 {
+    (void)d;
+
     conf_block  *b = conf_location_block;
     location    *loc = array_alloc(locations);
 
@@ -327,7 +335,7 @@ static const char *config_str_brace(const char *s, void *d)
 
 static const char *config_log_level(const char *s, void *d)
 {
-    const static char *level_str[] = {
+    static const char *level_str[] = {
             "debug",
             "info",
             "warn",
@@ -450,6 +458,7 @@ static const char *config_index(const char *s, void *d)
 
 static const char *config_comment(const char *s, void *d)
 {
+    (void)d;
     while (*s != '\0' && *s != '\n')
         ++s;
     return s;
diff --git a/event/connection.c b/event/connection.c
index 8ccd098..cb2937a 100644
--- a/event/connection.c
+++ b/event/connection.c
@@ -201,6 +201,8 @@ int conn_read(connection *conn, buffer *in)
 
 int conn_read_chunked(connection *conn, buffer *in)
 {
+    (void)conn;
+    (void)in;
     return FCY_ERROR;
 }
 
diff --git a/http/http.c b/http/http.c
index 8a23617..9686357 100644
--- a/http/http.c
+++ b/http/http.c
@@ -199,11 +199,11 @@ static void read_request_body(event *ev)
     /* content-length */
     if (rqst->has_content_length_header) {
         readable = buffer_readable_bytes(body_in);
-        if (readable >= rqst->content_length) {
+        if (readable >= (size_t)rqst->content_length) {
             goto done;
         }
         CONN_READ(conn, body_in, close_connection(conn));
-        if (buffer_readable_bytes(body_in) < rqst->content_length) {
+        if (buffer_readable_bytes(body_in) < (size_t)rqst->content_length) {
             return;
         }
     }
@@ -215,7 +215,7 @@ static void read_request_body(event *ev)
     /* 整个http请求解析和读取完毕 */
 done:
     readable = buffer_readable_bytes(body_in);
-    if (readable > rqst->content_length) {
+    if (readable > (size_t)rqst->content_length) {
         LOG_WARN("%s read extra request body", conn_str(conn));
         /* trunc */
         buffer_unwrite(body_in, readable - rqst->content_length);
@@ -479,7 +479,7 @@ static void upstream_read_response_body(event *ev)
     }
 
     if (upstm->has_content_length_header) {
-        if (buffer_readable_bytes(b) < upstm->content_length) {
+        if (buffer_readable_bytes(b) < (size_t)upstm->content_length) {
             return;
         }
         else {
diff --git a/http/request.c b/http/request.c
index 4a91166..43890ac 100644
--- a/http/request.c
+++ b/http/request.c
@@ -10,13 +10,13 @@
 #include "connection.h"
 #include "request.h"
 
-const static char *suffix_str[] = {
+static const char *suffix_str[] = {
         "html", "txt", "xml", "asp", "css",
         "gif", "ico", "png", "jpg", "js",
         "pdf", NULL,
 };
 
-const static char *content_type_str[] = {
+static const char *content_type_str[] = {
         "text/html; charset=utf-8",
         "text/plain; charset=utf-8",
         "text/xml",
@@ -42,6 +42,7 @@ static const char *get_content_type(string *suffix);
 
 int request_init(mem_pool *pool)
 {
+    (void)pool;
     return FCY_OK;
 }
 
@@ -194,6 +195,7 @@ void request_headers_htop(request *r, buffer *b)
 
 int request_read_chunked(request *r)
 {
+    (void)r;
     // TODO
     return FCY_ERROR;
 }