Prosecutors in Seminole County, Florida say they will not charge him because Nick's Gordon's gf, Laura Leal, recanted her original statement to law enforcement ... denying Nick had beaten her. Prosecutors also said without any independent witnesses they couldn't move forward with charges.

As we reported ... Nick was arrested for domestic violence after cops say Laura told them Nick struck her several times in the face. Nick's story was she threw a bottle at him, ripped his shirt and was acting crazy.

Remember, Nick's the one who called 911 and sounded frantic.

This lines up with what Laura told the judge in a letter ... begging for Nick to be freed because it was her fault since she's bipolar.