JENNIFER ANISTON is celebrating her 40th birthday today.

The actress will be celebrating with friends at a party in her Beverly Hills home this weekend.

Our spies tell us delivery trucks have been making housecalls to Jen's pad for the past week, delivering all sorts of goodies for Jen's big bash.

A black marquee tent has been erected at the front of her home where guests will roll up and valet their cars. A second marquee has been put up at the side of the house where it is believed the party with take place.

The party is expected to be a who's who of Hollywood with Jen's famous friends, including COURTENEY COX, DAVID ARQUETTE, LISA KUDROW, MATT LEBLANC, MATTHEW PERRY and boyfriend JOHN MAYER, amongst others.

Secret sources say BRAD PITT and ANGELINA JOLIE will not be bale to make the party as they are currently out of the US promoting their respective movies. Shame.


To see Jen's Life In Pics click here