EXCLUSIVE

Three time NBA champion Udonis Haslem just did something pretty awesome ... he bought a pretty sick 6 bedroom home for the woman who raised him ... just to say "thank you."

FYI -- the Miami Heat player's biological mother Debra battled drug addiction when Udonis was a child ... so he was raised by his stepmother ... Barbara Wooten.

Now, we've learned Haslem has hooked up Barbara with a brand new $326k pad in Miami Gardens -- it's 6 bedrooms, 4 baths, 3,640 square feet ... and Haslem foot the bill.

We reached out to Udonis for comment -- who told us, "I am blessed that God has provided me the opportunity and ability to provide for my family."

He added, "I wouldn't be here without her. She raised me since age 3. I can never repay her and all I can do is show my gratitude."