diff --git a/include/utils/logger.h b/include/utils/logger.h
index e731e59..66c8b42 100644
--- a/include/utils/logger.h
+++ b/include/utils/logger.h
@@ -1,6 +1,8 @@
 #ifndef _LOGGER_H_
 #define _LOGGER_H_
 
+#define LOG_PREFIX "ClearDNS"
+
 enum {
     LOG_DEBUG,
     LOG_INFO,
diff --git a/src/cleardns.c b/src/cleardns.c
index e66f8dc..42231de 100644
--- a/src/cleardns.c
+++ b/src/cleardns.c
@@ -1,3 +1,4 @@
+#include <stdio.h>
 #include "logger.h"
 #include "common.h"
 #include "dnsproxy.h"
@@ -28,11 +29,17 @@
 //    fprintf(stderr, "\"\n");
 //}
 
+
 int main(int argc, char *argv[]) { // ClearDNS server
 
     LOG_LEVEL = LOG_DEBUG;
     log_info("ClearDNS server start (%s)", VERSION);
 
+    FILE *fp = fopen("/dev/null/123", "r");
+    log_perror("Test prefix");
+
+    return 0;
+
 //    dnsproxy *domestic = dnsproxy_init(DOMESTIC_PORT);
 //
 //    dnsproxy_add_bootstrap(domestic, "1.1.1.1");
diff --git a/src/utils/logger.c b/src/utils/logger.c
index e9850ba..121132f 100644
--- a/src/utils/logger.c
+++ b/src/utils/logger.c
@@ -2,6 +2,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
+#include <sys/time.h>
 #include "logger.h"
 
 int LOG_LEVEL = LOG_INFO; // default log level
@@ -22,38 +23,37 @@ static const char *log_color[] = {
     "\x1b[95m", // fatal
 };
 
-// TODO: add ms field
+void fprint_prefix() { // print log prefix and time info
+    time_t _time;
+    time(&_time);
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    struct tm *t = localtime(&_time);
+    fprintf(stderr, "\x1b[36m[%s]\x1b[0m", LOG_PREFIX);
+    fprintf(stderr, " \x1b[90m%04d-%02d-%02d", t->tm_year + 1900, t->tm_mon + 1, t->tm_mday);
+    fprintf(stderr, " %02d:%02d:%02d.%03ld\x1b[0m", t->tm_hour, t->tm_min, t->tm_sec, tv.tv_usec / 1000);
+}
+
 void log_printf(int level, const char *fmt, ...) {
     if (level < LOG_LEVEL) { // skip low log level
         return;
     }
-    time_t t = time(NULL);
-    char time_str[20]; // YYYY-mm-dd HH:MM:SS (20 bytes)
-    time_str[strftime(time_str, 20, "%Y-%m-%d %H:%M:%S", localtime(&t))] = '\0'; // generate time str
-
     va_list ap;
     va_start(ap, fmt);
-    fprintf(stderr, "\x1b[36m[ClearDNS]\x1b[0m \x1b[90m%s\x1b[0m", time_str); // show log prefix
+    fprint_prefix();
     fprintf(stderr, " %s%s\x1b[0m ", log_color[level], log_string[level]); // show log level
     vfprintf(stderr, fmt, ap); // output log content
     fprintf(stderr, "\n"); // add LF after line
     fflush(stderr);
     va_end(ap);
-
     if (level == LOG_FATAL) {
         exit(1);
     }
 }
 
-// TODO: add ms field
 void log_perror(char *prefix) {
-    time_t t;
-    time(&t);
-    struct tm *lt = localtime(&t);
-    fprintf(stderr, "\x1b[36m[ClearDNS]\x1b[0m ");
-    fprintf(stderr, "\x1b[90m%04d-%02d-%02d %02d:%02d:%02d\x1b[0m",
-            lt->tm_year + 1900, lt->tm_mon, lt->tm_mday, lt->tm_hour, lt->tm_min, lt->tm_sec);
-    fprintf(stderr, " %s%s\x1b[0m ", log_color[3], log_string[3]); // error level
+    fprint_prefix();
+    fprintf(stderr, " %s%s\x1b[0m ", log_color[LOG_ERROR], log_string[LOG_ERROR]);
     fflush(stderr);
     perror(prefix);
 }