Best Blackhat Forum

hello , if i have wordpress site and many users , each user post his posts and videos , i want other user to follow each other and when every user open the site , he saw the recent posts of the users he follow him ...
for example : when i open youtube , i saw the recent videos of users of channels i follow
is any plugin or script to do that ?

I think I understand what you wanted.
This plugin lets you follow authors in a Twitter fashion.
http://wordpress.org/plugins/buddypress-followers/

i setup this plugin , but when i press follow for user , it send to my email any new post of him , but i don't want that .. i want to see in the home page of the site the posts of user i follow like youtube :)

Don't know about that. There is a plugin for just about anything you can imagine.
Do lots of Google searches.
Maybe finding a YouTube clone script would be easier than modifying the way WP operates.
Good luck. Let me know if I can help any other way.