Kanye West -- D.A. Declines Prosecution of Bev Hills Beating Case

Kanye West will NOT be prosecuted for beating up a guy in the waiting room of a Beverely Hills chiropractor ... TMZ has learned.

The L.A. County D.A. has REJECTED the case. As for why ... the D.A. gave several reasons:

-- A civil compromise has been reached. TMZ broke the story, Kanye agreed to pay more than $250,000 to the 18-year-old.

-- The victim was not hurt. The D.A. says "No significant injuries were documented."

-- The victim became uncooperative after the civil compromise, and would not speak with prosecutors.

The conclusion of the D.A. ... "Prosecution is accordingly declined due to Victim unavailability."