diff --git a/README.md b/README.md
index e4bda7371..1b6da7837 100644
--- a/README.md
+++ b/README.md
@@ -3,14 +3,23 @@ This is Telegram API for python.
 Main aim is to implement MTProto protocol Telegram API on pure Python (not wrapped CLI)
 We'll try to make it work on Python 2 as well as 3.
 
-Detailed description of API and protokol can be found here:
+Detailed description of API and protocol can be found here:
 https://core.telegram.org/api
 https://core.telegram.org/mtproto
 
-Repo doesn't contain any credentials to connect Telegram servers.
-You can get your credentials from http://my.telegram.org
+# Structure
 
-You shoud plase in the root of your repo 2 files:
+- mtproto.py 
+- testing.py
+- prime.py
+- credentials
+- rsa.pub
+
+## Credentials
+Repo doesn't contain any credentials to connect Telegram servers.
+You can get yours from http://my.telegram.org
+
+You should place 2 files in the root of your repo:
 - credentials
 - rsa.pub
 
@@ -25,11 +34,25 @@ port: 443
 ```
 rsa.pub contains your RSA key.
 
+## mtproto.py
 
-# testing.py
+Contains functions to work with MTproto protocol:
+- TL schema parsing
+- serializing and deserializing
+- manage connections to server
+- send and receive messages
+
+## testing.py
 
 testing.py is used to test functionality of modules.
 Now it makes steps from https://core.telegram.org/mtproto/samples-auth_key:
 - sends PQ request to server
 - parses the result
 - factorizes PQ
+ 
+## prime.py
+prime.py is used in PQ factorization. It has been copied from https://stackoverflow.com/questions/4643647/fast-prime-factorization-module
+
+## TL schema
+We use JSON format TL Shema. TL Schema file contains information about objects and methods, it is located in TL_schema.JSON file in the root of repo. It is fully equivalent to JSON TL Schema from
+https://core.telegram.org/schema/mtproto-json