A lockable rotary cutting mat includes a base plate and a rotary plate. The central bottom portion of the rotary plate is assembled on the center of the base plate through a rotary connector. The rotary plate includes a cutting surface and a periphery. The periphery is formed with concave edge portions, and a locking component is provided at the corresponding position between the base plate and the rotary plate periphery. The locking component includes a moving base, a controller and a locking edge portion. The controller can be pushed along a movement guiding axis on the moving base. The locking edge portion is connected to, and can be driven by the controller to have locked and released positions. When the locking edge portion is at the locked position, it is aligned to, and is engaged with the corresponding concave edge portion, so that the rotary plate is fixed.