A computer mouse is provided and has a mouse main body, a rubber cover and a foot pad. The mouse main body has engagement holes. The rubber cover is covered on the mouse main body and formed with an opening. The foot pad has a flat foot-pad main body which has engagement members, each of which has a connection portion. The connection portion has a first end connected to the engagement member and having a height matched with that of the engagement hole, and a second end protruded to form an umbrella-like engagement portion. When installing the computer mouse, the connection portion passes through the opening and is then received in the engagement hole, and the engagement portion is engaged against an inner edge of the engagement hole, so that the foot pad is firmly mounted on the computer mouse. Thus, the computer mouse has simpler installation and aesthetic appearance.