I have installed lync server 2013 downloaded it from official microsoft site, when free trial expires will lync server work or not , or some features will be disabled?

It should no longer work, but you could upgrade it to the full version once you're licensed using the following:

https://technet.microsoft.com/en-us/library/gg521005.aspx

Hi shototadumadze,

The evaluation version will expire 180 days after it was installed and the Lync services will be no longer started.

You must update the license before it expires.

 

Best regards,

Eric