You can use a sequence alignment tool, such as Cobalt:

http://www.st-va.ncbi.nlm.nih.gov/tools/cobalt/re_cobalt.cgi?

Hi, You can use blast software in NCBI. In the first page click on Blast, then in the new window, click on protein sequence in the below left.

Hello, you can use protein BLAST tool by NCBI or ClustalW2 by EBI

Regards!

Thank you all ! I used BLAST, its very easy !