diff --git a/README.md b/README.md
index 3bfbdcee..4794edc8 100644
--- a/README.md
+++ b/README.md
@@ -44,6 +44,7 @@
 * [Turn on debug mode in Amavisd](https://bitbucket.org/zhb/docs.iredmail.org/src/default/troubleshooting/turn.on.debug.mode.in.amavisd.md)
 * [Turn on debug mode in Cluebringer](https://bitbucket.org/zhb/docs.iredmail.org/src/default/troubleshooting/turn.on.debug.mode.in.cluebringer.md)
 * [Turn on debug mode in Dovecot](https://bitbucket.org/zhb/docs.iredmail.org/src/default/troubleshooting/turn.on.debug.mode.in.dovecot.md)
+* [Turn on debug mode in iRedAPD](https://bitbucket.org/zhb/docs.iredmail.org/src/default/troubleshooting/turn.on.debug.mode.in.iredapd.md)
 * [Turn on debug mode in OpenLDAP](https://bitbucket.org/zhb/docs.iredmail.org/src/default/troubleshooting/turn.on.debug.mode.in.openldap.md)
 # Frequently Asked Questions
 * [Locations of configuration and log files of mojor components](https://bitbucket.org/zhb/docs.iredmail.org/src/default/faq/file.locations.md)
diff --git a/html/index.html b/html/index.html
index 1ff2eff6..817e52c4 100644
--- a/html/index.html
+++ b/html/index.html
@@ -70,6 +70,7 @@
 <li><a href="turn.on.debug.mode.in.amavisd.html">Turn on debug mode in Amavisd</a></li>
 <li><a href="turn.on.debug.mode.in.cluebringer.html">Turn on debug mode in Cluebringer</a></li>
 <li><a href="turn.on.debug.mode.in.dovecot.html">Turn on debug mode in Dovecot</a></li>
+<li><a href="turn.on.debug.mode.in.iredapd.html">Turn on debug mode in iRedAPD</a></li>
 <li><a href="turn.on.debug.mode.in.openldap.html">Turn on debug mode in OpenLDAP</a></li>
 </ul>
 <h3 id="frequently-asked-questions">Frequently Asked Questions</h3>
diff --git a/html/turn.on.debug.mode.in.iredapd.html b/html/turn.on.debug.mode.in.iredapd.html
new file mode 100644
index 00000000..1d68c7e6
--- /dev/null
+++ b/html/turn.on.debug.mode.in.iredapd.html
@@ -0,0 +1,35 @@
+<html>
+    <head>
+        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+        <title>Turn on debug mode in iRedAPD</title>
+        <link href="./css/markdown.css" rel="stylesheet"></head>
+    </head>
+    <body>
+    
+    <div id="navigation">
+        <a href="http://www.iredmail.org" target="_blank">iRedMail web site</a>
+    
+        // <a href="./index.html">Document Index</a>
+    </div><h1 id="turn-on-debug-mode-in-iredapd">Turn on debug mode in iRedAPD</h1>
+<p>To turn on debug mode in iRedAPD, please set its log level to 'debug' in
+iRedAPD config file <code>/opt/iredapd/settings.py</code>, then restart iRedAPD
+service.</p>
+<pre><code># Log level: info, debug.
+log_level = 'debug'
+</code></pre>
+
+<p>iRedAPD is configured to log to <code>/var/log/iredapd.log</code> by default, so
+please monitor this file to check detailed debug log.</p><br /><p style="text-align: center;">If you found something wrong
+in this document, please do
+<a href="http://www.iredmail.org/contact.html">contact us</a> to fix it.</p><p style="text-align: center; color: grey;">This tutorial is published under a <a href="http://creativecommons.org/licenses/by-nd/3.0/us/" target="_blank">CC BY-ND 3.0</a> license.<!-- Google Analytics -->
+<script type="text/javascript">
+    var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
+    document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
+</script>
+<script type="text/javascript">
+    try {
+        var pageTracker = _gat._getTracker("UA-3293801-14");
+        pageTracker._trackPageview();
+    } catch(err) {}
+</script>
+</body></html>
\ No newline at end of file
diff --git a/troubleshooting/turn.on.debug.mode.in.iredapd.md b/troubleshooting/turn.on.debug.mode.in.iredapd.md
new file mode 100644
index 00000000..8825e246
--- /dev/null
+++ b/troubleshooting/turn.on.debug.mode.in.iredapd.md
@@ -0,0 +1,13 @@
+# Turn on debug mode in iRedAPD
+
+To turn on debug mode in iRedAPD, please set its log level to 'debug' in
+iRedAPD config file `/opt/iredapd/settings.py`, then restart iRedAPD
+service.
+
+```
+# Log level: info, debug.
+log_level = 'debug'
+```
+
+iRedAPD is configured to log to `/var/log/iredapd.log` by default, so
+please monitor this file to check detailed debug log.
