A front cover assembly is proposed, which includes a frame, a cover glass, and a waterproof glue. The frame includes an receiving cavity, which includes a first wall and a second wall. The cover glass is partially received in the frame. A first lateral face of the cover glass has a step portion disposed at a peripheral area thereof. The step portion surrounds the first lateral face. The waterproof glue is disposed on the step portion and covers the step portion to fill a gap between the cover glass and the frame. This assembly can prevent water or dust from entering a terminal device.