how to customize user profile page I want to customize user profile page as per my own way.
I have created one file named as page--user.tpl.php, but after making changes in this file during user logged in, the changes reflects on sign up(register page) without logged in.
But i only wants to change the look and feel of individual user's page.

Please help me.

Thanks
You've simply used the wrong template. page--user.tpl.php affects "user pages" like, as you've discovered, the user login.

The template you want to create and modify is user-profile.tpl.php https://api.drupal.org/api/drupal/modules%21user%21user-profile.tpl.php/7