Jermaine Dupri has been partying hard lately in celebration of So So Def's 20 year anniversary.  And last night, on the eve of the big So So Def Anniversary concert, celebs turned up for the private VIP Castle Party at Summerour Studio in Atlanta.

We've got the pics of J.D., Bow Wow, Da Brat, Trina Braxton and more....

Photog Paras Griffin snapped pics of celebs like J.D. celebrating the night before the So So Def anniversary concert (going down tonight at the Fox Theater in ATL) with his homies like Anthony Hamilton and Bryan Michael-Cox.  Mr. Dupri brought some major hits in the 90's, so it's only right the label celebrates.

Trina Braxton is still with her hubby Gabe apparently.

She kept it simple in a fitted black dress and mirrored blue pumps.

Da Brat reached into her 90's closet--which is her normal closet--to put on her tomboy oversized tee and camo with a neon green MCM backpack.

Oh Brat.

SoSo Def newbie Dondria rocked a black cutout dress for the party.

JD's business partner & dad Michael Mauldin came out to party too.

Bow Wow jetted to ATL to get back to his Def roots.  And he hit the DJ booth with V103 host Big Tigger.

Bow's "106 & Park" co-host Shorty Da Prince went down to support too.

T-Pain and his beard made an appearance.

So did Jagged Edge and friends.

DTP's Chaka Zulu came out to support.

Wonder if Darrin Henson is still making workout videos somewhere.

"Football Wives" former star Chanita Foster was at the party.

And "Big Rich Atlanta" stars Sharlinda & Kahdijiha Parker brought their wiggery to the event.

V103 host Egypt hit the carpet with her hubby.

Raheem DaVaughn kept it bald.

And designer Mychael Knight showed off his designs on the carpet with "his model".

Fun times.

Photo Credit: Paras Griffin/gparasphotography.com