Chris Brown's Party House is Closed to Randoms

Chris Brown is done hosting frat house parties ... blaming his male friends and thirsty chicks for his recent arrest.

Our Chris sources tell us he's now enforcing a strict guest policy at his Calabasas mansion -- and letting everyone in his crew know he's as serious as death ... no more randoms allowed.

We told he's pulling back on parties for starters, but there's this problem with his 2 roommates/best friends. They now have to submit a guest list to Chris IN WRITING, and they must describe who they are with sufficient details so he can decide whether he wants them in his home.

We're told he also is imposing another strict policy ... guests are prohibited from bringing drugs or alcohol. The only booze and drugs allowed are his.