An electrical connector assembly comprises a first connector, and a second connector mounted onto the first connector, a frame surrounding the connectors, a locking member, and a lever assemble the locking member to the frame. The locking member has a main body pivoting to the frame, a supporting portion being seated by the lever and a pushing portion. The main body locks the second connector, a user can press the lever to make the locking member to rotate, then to release the second connector, and upwardly push the second connector to apart the second connector from the first connector.