why My iphone SE freezes when I use my CONTACTS ?

Hi farhadgo, 

Thank you for using Apple Support Communities. 

We see from your post that you have an issue with your iPhone freezing up when using Contacts. We want to help. You can look at the steps in this article that talks about If your iPhone, iPad, or iPod touch won't turn on or is frozen - Apple Support.

Also, is your iPhone updated to the most recent version for that model? That would be a good next step. It is always a good idea to have a backup of your iPhone before updating. 

Here’s How to back up your iPhone, iPad, and iPod touch - Apple Support

Here’s how to Update your iPhone, iPad, or iPod touch - Apple Support 

Hope that helps.

Best Regards!