diff --git a/README.rst b/README.rst
index 97565303..8d522a5d 100644
--- a/README.rst
+++ b/README.rst
@@ -33,6 +33,21 @@ After writing your application, just type::
    % ryu-manager yourapp.py
 
 
+Optional Requirements
+=====================
+
+Some functionalities of ryu requires extra packages:
+
+- OF-Config requires lxml
+- NETCONF requires paramiko
+- BGP speaker (net_cntl) requires paramiko
+
+If you want to use the functionalities, please install requirements::
+
+    % pip install lxml
+    % pip install paramiko
+
+
 Support
 =======
 Ryu Official site is `<http://osrg.github.io/ryu/>`_.
diff --git a/tools/pip-requires b/tools/pip-requires
index d06342a9..5753ce52 100644
--- a/tools/pip-requires
+++ b/tools/pip-requires
@@ -1,9 +1,7 @@
 eventlet
-lxml  # OF-Config
 msgpack-python>=0.3.0  # RPC library, BGP speaker(net_cntl)
 netaddr
 oslo.config>=1.2.0
-paramiko  # NETCONF, BGP speaker
 routes  # wsgi
 six>=1.4.0
 webob>=1.2  # wsgi
diff --git a/tools/test-requires b/tools/test-requires
index 2ffd739b..06b8c548 100644
--- a/tools/test-requires
+++ b/tools/test-requires
@@ -4,3 +4,5 @@ nose
 pep8
 pylint==0.25.0
 xml_compare
+lxml  # OF-Config
+paramiko  # NETCONF, BGP speaker