Trey Songz won't face a felony criminal charge for allegedly hitting a woman, because the L.A. District Attorney isn't buying the case ... TMZ has learned.

Law enforcement sources tell us... the singer's lawyer,Shawn Holley, gave numerous witness statements to LAPD that contradicted Andrea Buera's account of events during NBA All-Star Weekend in February.

We're told Holley also provided further info that led to skepticism about Buera's credibility.

The case will now be referred to the L.A. City Attorney, who will decide whether or not to charge Songz with the lesser charge of misdemeanor domestic violence.

As we reported ... Buera claims Songz assaulted he rat a Hollywood Hills party because he was mad she was talking to another man, and beat her so badly she vomited from a concussion.

Songzsurrendered to authorities a few days later, but maintained he was "being lied on and falsely accused for someone's personal gain."