Abstract: A top mounting faucet assembly is mounted on a kitchen basin having an opening and contains: a fixer, a body, and a locking bolt. The fixer includes a base and a clamper, wherein the base includes a support portion and an insertion portion, and the support portion includes a peripheral fence and a shoulder, the peripheral fence has a recessed portion and a first anti-rotation portion, the shoulder has two longitudinal holes, and the insertion portion has a cylindrical fence and two columns. The clamper contains two screw rods and two locking protrusions. The body includes a second anti-rotation portion and a threaded orifice. The locking bolt screws with the threaded orifice of the body and abuts against the recessed portion of the base so that the body is stopped and does not move along the base, hence the body does not upwardly remove from the base.