diff --git a/pom.xml b/pom.xml
index b443770..161d62f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -34,7 +34,7 @@
         <developerConnection>scm:git:git@github.com:code4craft/webmagic.git</developerConnection>
         <url>git@github.com:code4craft/webmagic.git</url>
       <tag>webmagic-parent-0.6.1</tag>
-  </scm>
+    </scm>
     <licenses>
         <license>
             <name>Apache License, Version 2.0</name>
diff --git a/webmagic-core/pom.xml b/webmagic-core/pom.xml
index e889cd4..66e455d 100644
--- a/webmagic-core/pom.xml
+++ b/webmagic-core/pom.xml
@@ -48,6 +48,7 @@
         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-log4j12</artifactId>
+            <optional>true</optional>
         </dependency>
 
         <dependency>
diff --git a/webmagic-extension/src/main/java/us/codecraft/webmagic/example/PatternProcessorExample.java b/webmagic-extension/src/main/java/us/codecraft/webmagic/example/PatternProcessorExample.java
index 8ecb08f..9406abf 100644
--- a/webmagic-extension/src/main/java/us/codecraft/webmagic/example/PatternProcessorExample.java
+++ b/webmagic-extension/src/main/java/us/codecraft/webmagic/example/PatternProcessorExample.java
@@ -1,6 +1,8 @@
 package us.codecraft.webmagic.example;
 
-import org.apache.log4j.Logger;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import us.codecraft.webmagic.*;
 import us.codecraft.webmagic.handler.CompositePageProcessor;
 import us.codecraft.webmagic.handler.CompositePipeline;
@@ -15,7 +17,7 @@ import us.codecraft.webmagic.handler.RequestMatcher;
  */
 public class PatternProcessorExample {
 
-    private static Logger log = Logger.getLogger(PatternProcessorExample.class);
+    private static Logger log = LoggerFactory.getLogger(PatternProcessorExample.class);
 
     public static void main(String... args) {
 
diff --git a/webmagic-saxon/src/main/java/us/codecraft/webmagic/selector/Xpath2Selector.java b/webmagic-saxon/src/main/java/us/codecraft/webmagic/selector/Xpath2Selector.java
index 98b1efe..d8aab6c 100644
--- a/webmagic-saxon/src/main/java/us/codecraft/webmagic/selector/Xpath2Selector.java
+++ b/webmagic-saxon/src/main/java/us/codecraft/webmagic/selector/Xpath2Selector.java
@@ -2,11 +2,12 @@ package us.codecraft.webmagic.selector;
 
 import net.sf.saxon.lib.NamespaceConstant;
 import net.sf.saxon.xpath.XPathEvaluator;
-import org.apache.log4j.Logger;
 import org.htmlcleaner.CleanerProperties;
 import org.htmlcleaner.DomSerializer;
 import org.htmlcleaner.HtmlCleaner;
 import org.htmlcleaner.TagNode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
@@ -40,7 +41,7 @@ public class Xpath2Selector implements Selector {
 
     private XPathExpression xPathExpression;
 
-    private Logger logger = Logger.getLogger(getClass());
+    private Logger logger = LoggerFactory.getLogger(getClass());
 
     public Xpath2Selector(String xpathStr) {
         this.xpathStr = xpathStr;
diff --git a/webmagic-scripts/pom.xml b/webmagic-scripts/pom.xml
index 22956cb..9dbc7b3 100755
--- a/webmagic-scripts/pom.xml
+++ b/webmagic-scripts/pom.xml
@@ -49,6 +49,10 @@
             <artifactId>webmagic-core</artifactId>
             <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-log4j12</artifactId>
+        </dependency>
         <dependency>
             <groupId>us.codecraft</groupId>
             <artifactId>webmagic-extension</artifactId>
diff --git a/webmagic-selenium/src/main/java/us/codecraft/webmagic/downloader/selenium/SeleniumDownloader.java b/webmagic-selenium/src/main/java/us/codecraft/webmagic/downloader/selenium/SeleniumDownloader.java
index f45f7e2..cce293f 100644
--- a/webmagic-selenium/src/main/java/us/codecraft/webmagic/downloader/selenium/SeleniumDownloader.java
+++ b/webmagic-selenium/src/main/java/us/codecraft/webmagic/downloader/selenium/SeleniumDownloader.java
@@ -1,10 +1,12 @@
 package us.codecraft.webmagic.downloader.selenium;
 
-import org.apache.log4j.Logger;
 import org.openqa.selenium.By;
 import org.openqa.selenium.Cookie;
 import org.openqa.selenium.WebDriver;
 import org.openqa.selenium.WebElement;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import us.codecraft.webmagic.Page;
 import us.codecraft.webmagic.Request;
 import us.codecraft.webmagic.Site;
@@ -29,7 +31,7 @@ public class SeleniumDownloader implements Downloader, Closeable {
 
 	private volatile WebDriverPool webDriverPool;
 
-	private Logger logger = Logger.getLogger(getClass());
+	private Logger logger = LoggerFactory.getLogger(getClass());
 
 	private int sleepTime = 0;
 
diff --git a/webmagic-selenium/src/main/java/us/codecraft/webmagic/downloader/selenium/WebDriverPool.java b/webmagic-selenium/src/main/java/us/codecraft/webmagic/downloader/selenium/WebDriverPool.java
index 1472cb3..e1d9dd0 100644
--- a/webmagic-selenium/src/main/java/us/codecraft/webmagic/downloader/selenium/WebDriverPool.java
+++ b/webmagic-selenium/src/main/java/us/codecraft/webmagic/downloader/selenium/WebDriverPool.java
@@ -1,6 +1,5 @@
 package us.codecraft.webmagic.downloader.selenium;
 
-import org.apache.log4j.Logger;
 import org.openqa.selenium.WebDriver;
 import org.openqa.selenium.chrome.ChromeDriver;
 import org.openqa.selenium.firefox.FirefoxDriver;
@@ -8,6 +7,8 @@ import org.openqa.selenium.phantomjs.PhantomJSDriver;
 import org.openqa.selenium.phantomjs.PhantomJSDriverService;
 import org.openqa.selenium.remote.DesiredCapabilities;
 import org.openqa.selenium.remote.RemoteWebDriver;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.FileReader;
 import java.io.IOException;
@@ -27,7 +28,7 @@ import java.util.concurrent.atomic.AtomicInteger;
  *         Time: 下午1:41 <br>
  */
 class WebDriverPool {
-	private Logger logger = Logger.getLogger(getClass());
+	private Logger logger = LoggerFactory.getLogger(getClass());
 
 	private final static int DEFAULT_CAPACITY = 5;