diff --git a/docs/conf.py b/docs/conf.py
index 51e185639..bed869fd7 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -14,13 +14,14 @@
 #
 import os
 import sys
+from datetime import date
 sys.path.insert(0, os.path.abspath('..'))
 
 
 # -- Project information -----------------------------------------------------
 
 project = 'dpdata'
-copyright = '2019, Han Wang'
+copyright = '2019-%d, Deep Modeling ' % date.today().year
 author = 'Han Wang'
 
 # The short X.Y version
@@ -39,11 +40,12 @@
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 extensions = [
-    'sphinxcontrib.napoleon',
+    'sphinx_rtd_theme',
     'sphinx.ext.mathjax',
     'sphinx.ext.viewcode',
-    'sphinx.ext.githubpages',
-    'm2r',
+    'sphinx.ext.intersphinx',
+    'numpydoc',
+    'm2r2',
 ]
 
 # Add any paths that contain templates here, relative to this directory.
@@ -79,7 +81,7 @@
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 #
-html_theme = 'alabaster'
+html_theme = 'sphinx_rtd_theme'
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
@@ -90,7 +92,7 @@
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = ['_static']
+#html_static_path = ['_static']
 
 # Custom sidebar templates, must be a dictionary that maps document names
 # to template names.
@@ -161,3 +163,18 @@
 
 
 # -- Extension configuration -------------------------------------------------
+def run_apidoc(_):
+    from sphinx.ext.apidoc import main
+    sys.path.append(os.path.join(os.path.dirname(__file__), '..'))
+    cur_dir = os.path.abspath(os.path.dirname(__file__))
+    module = os.path.join(cur_dir, "..", "dpdata")
+    main(['-M', '--tocfile', 'api', '-H', 'API documentation', '-o', os.path.join(cur_dir, "api"), module, '--force'])
+
+def setup(app):
+    app.connect('builder-inited', run_apidoc)
+
+
+intersphinx_mapping = {
+    "numpy": ("https://docs.scipy.org/doc/numpy/", None),
+    "python": ("https://docs.python.org/", None),
+}
diff --git a/docs/index.rst b/docs/index.rst
index 5ea8253f2..116e3f690 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -10,22 +10,11 @@ Welcome to dpdata's documentation!
    :maxdepth: 2
    :caption: Contents:
 
+   api/api
 
 .. mdinclude:: ../README.md
 
 
-API documentation
-=================
-
-.. automodule:: dpdata
-
-.. autoclass:: System
-    :members: __init__, __getitem__, get_nframes, get_natoms, sub_system, append, apply_pbc, to_lammps_lmp, to_vasp_poscar
-
-.. autoclass:: LabeledSystem
-    :members: __init__, sub_system, to_deepmd_raw, to_deepmd_npy
-
-
 Indices and tables
 ==================
 
diff --git a/docs/requirements.txt b/docs/requirements.txt
new file mode 100644
index 000000000..e9704b8eb
--- /dev/null
+++ b/docs/requirements.txt
@@ -0,0 +1 @@
+.[docs]
diff --git a/setup.py b/setup.py
index 59133b924..c0ded7819 100644
--- a/setup.py
+++ b/setup.py
@@ -53,6 +53,7 @@
         'ase': ['ase'],
         'amber': ['parmed'],
         'pymatgen': ['pymatgen'],
+        'docs': ['sphinx', 'recommonmark', 'sphinx_rtd_theme>=1.0.0rc1', 'numpydoc', 'm2r2'],
     }
 )