A suitcase lock that can be opened either by setting a combination or by a key, in which dials of a suitcase lock are disposed with sleeves, and characterized in that a key tumbler is additionally fitted to the suitcase lock, and tongues located at a lower portion of a swing plate clamp connect to a slider. A groove at one end of the slider enables a push rod of the key tumbler to be clamped therein, and sloping grooves defined on another end enable the tongues of the swing plate to displace therein. In general, dials are used to control cuttings or circular arcs on the sleeves to operate the swing plate and hooking to a locked object and realize opening and closing of the lock. However, when in a locked state, without moving the dials, a key can be used to directly activate the key tumbler to push the slider, and thereby causes the swing plate to tilt in an opposite direction and the stopper at one end of swing plate can release the locked object from hooking position, thus opening the lock or suitcase.