Abstract: A motorcycle lock includes a base, a locking device, a locking rod, a stop plate, a fix plate, a constrictor and a housing. The locking device consists of a base block, a slide block and a position plate. The stop plate hides the locking device located in the base to prevent the lock from being unlocked illegally, and the base with the housing is fixed on a front fork of a motorcycle by a constrictor. In locking, a push plate is swung 90 degrees to align it with the locking rod and push it rearward into a front wheel, in thus locking the wheel without using the key and hampering the front wheel from rotating. In unlocking a key is used to permit the locking rod to retreat to its original unlocked position by a spring.