The present disclosure relates to a mask plate, an exposure method thereof, and a liquid crystal display panel including the mask plate. On the mask plate, a plurality of pattern regions is arranged in a gradient variation from the center of the mask plate to the edges thereof according to the deformation degree of the exposure mask. The method for exposing the mask plate comprises the following steps of, (a) providing an exposure mask in a horizontal state, and measuring the deformation degree of the exposure mask; (b) arranging, on the mask plate, a plurality of pattern regions, the dimensions of which change in a gradient manner from the center of the mask plate to the edges thereof according to the deformation degree of the exposure mask; and (c) completing the exposure of the mask plate. The mask plate according to the present disclosure can compensate the effect of deformation of the exposure mask on the exposure area of the mask plate.