diff --git a/engine.go b/engine.go
index 85eb488f..413c482a 100644
--- a/engine.go
+++ b/engine.go
@@ -37,7 +37,7 @@ type Engine struct {
 	ShowDebug bool
 	ShowWarn  bool
 
-	Logger     ILogger // io.Writer
+	Logger     core.ILogger
 	TZLocation *time.Location
 }
 
diff --git a/logger.go b/logger.go
index f9d529a1..5ae18906 100644
--- a/logger.go
+++ b/logger.go
@@ -6,41 +6,51 @@ import (
 	"log"
 )
 
-// logger interface, log/syslog conform with this interface
-type ILogger interface {
-	Debug(m string) (err error)
-	Err(m string) (err error)
-	Info(m string) (err error)
-	Warning(m string) (err error)
-}
+type LogLevel int
+
+const (
+	LOG_ERR LogLevel = iota + 3
+	LOG_WARNING
+	LOG_INFO = iota + 6
+	LOG_DEBUG
+)
+
+const (
+	DEFAULT_LOG_PREFIX = "[xorm]"
+	DEFAULT_LOG_FLAG   = log.Ldate | log.Lmicroseconds
+	DEFAULT_LOG_LEVEL  = LOG_INFO
+)
 
 type SimpleLogger struct {
-	DEBUG *log.Logger
-	ERR   *log.Logger
-	INFO  *log.Logger
-	WARN  *log.Logger
+	DEBUG    *log.Logger
+	ERR      *log.Logger
+	INFO     *log.Logger
+	WARN     *log.Logger
+	LogLevel LogLevel
 }
 
 func NewSimpleLogger(out io.Writer) *SimpleLogger {
-	return &SimpleLogger{
-		DEBUG: log.New(out, "[xorm] [debug] ", log.Ldate|log.Lmicroseconds),
-		ERR:   log.New(out, "[xorm] [error] ", log.Ldate|log.Lmicroseconds),
-		INFO:  log.New(out, "[xorm] [info]  ", log.Ldate|log.Lmicroseconds),
-		WARN:  log.New(out, "[xorm] [warn]  ", log.Ldate|log.Lmicroseconds),
-	}
+	return NewSimpleLogger2(out, DEFAULT_LOG_PREFIX, DEFAULT_LOG_FLAG)
 }
 
 func NewSimpleLogger2(out io.Writer, prefix string, flag int) *SimpleLogger {
+	return NewSimpleLogger3(out, prefix, flag, DEFAULT_LOG_LEVEL)
+}
+
+func NewSimpleLogger3(out io.Writer, prefix string, flag int, logLevel LogLevel) *SimpleLogger {
 	return &SimpleLogger{
-		DEBUG: log.New(out, fmt.Sprintf("%s [debug] ", prefix), log.Ldate|log.Lmicroseconds),
-		ERR:   log.New(out, fmt.Sprintf("%s [error] ", prefix), log.Ldate|log.Lmicroseconds),
-		INFO:  log.New(out, fmt.Sprintf("%s [info]  ", prefix), log.Ldate|log.Lmicroseconds),
-		WARN:  log.New(out, fmt.Sprintf("%s [warn]  ", prefix), log.Ldate|log.Lmicroseconds),
+		DEBUG:    log.New(out, fmt.Sprintf("%s [debug] ", prefix), flag),
+		ERR:      log.New(out, fmt.Sprintf("%s [error] ", prefix), flag),
+		INFO:     log.New(out, fmt.Sprintf("%s [info]  ", prefix), flag),
+		WARN:     log.New(out, fmt.Sprintf("%s [warn]  ", prefix), flag),
+		LogLevel: LOG_INFO,
 	}
 }
 
 func (s *SimpleLogger) Debug(m string) (err error) {
-	s.DEBUG.Println(m)
+	if s.LogLevel >= LOG_DEBUG {
+		s.DEBUG.Println(m)
+	}
 	return
 }
 
@@ -50,11 +60,15 @@ func (s *SimpleLogger) Err(m string) (err error) {
 }
 
 func (s *SimpleLogger) Info(m string) (err error) {
-	s.INFO.Println(m)
+	if s.LogLevel >= LOG_INFO {
+		s.INFO.Println(m)
+	}
 	return
 }
 
 func (s *SimpleLogger) Warning(m string) (err error) {
-	s.WARN.Println(m)
+	if s.LogLevel >= LOG_WARNING {
+		s.WARN.Println(m)
+	}
 	return
 }