Kim Kardashian To Kanye West -- Your Birthday Ain’t Over Yet … Wait Till We Get Home

Kim Kardashian stuck with the BALLS theme for Kanye West's birthday, because when he got home from playing hoops at Staples Center with his boys ... she dropped another surprise on him.

Kim tipped off part TWO of Yeezy's birthday by unveiling his very own basketball sanctuary ... IN HIS BACKYARD!!

While Kanye was shooting around with celebrity friends on Monday, Kim had construction crews break ground on the new home court going up at at their home.

All in all , the 7,000 sq. ft addition to their Hidden Hills mansion will include the tricked out basketball court AND a glam room -- probably a little gift for KK herself.

All this, just for his 38th. Ye's 4-0 is gonna be ridic.