You can start a conversation with him, then get some article or book about the same topic to read, in this way he maybe interested to read more about the subject you were talking about.
Start reading to him on daily basis for 2-4 weeks without asking him to read, then let him participate with you.
check this article for more tips :
http://babyhelpguide.com/when-should-a-child-learn-to-read/ Thank you too much for your replay I will follow as you said