Abstract: A object storing case of a motorcycle includes a connecting part disposed in a recess of a rear side of a holding body thereo, a fixing plate pivoted to the connecting part at the middle, a locking member and an operating member. The locking member is pivoted to the connecting part, and the fixing plate is pivoted to the locking member at a lower end such that the locking member can be turned for moving the fixing plate between an engaging position and a disengaging one in relation to a cover of the case. The locking member is equipped with a combination lock, and has a sloping slot extending from the lower edge, through which a spindle of the operating member is passed. The operating member further has a commoving pole associated with a stopping plate capable of being locked with the combination lock.