Abstract: The present disclosure provides a lock assembly for a bag, wherein the bag has a bag body and a bag flap, the assembly comprising: a body-side sub-assembly secured to the bag body; and a flap-side sub-assembly secured to the bag flap, wherein the body-side sub-assembly comprises: a base member having a rear portion secured to the bag body, a pair of rotation members, each rotation member including an upper grip and a lower shaft extending from the upper grip, a rotation-force transfer mechanism configured to transfer a rotation force between the pair of rotation members, wherein the rotation-force transfer mechanism employs a belt.