Thoressa maculata sp. nov., from Mt. Maoershan, Xinan County, Guangxi Province is described and illustrated. The new species resembles T. hyrie and T. luanchuanensis, but it can be distinguished from hyrie by the spots in spaces M₃ and Cu₁ overlapping on forewing, hindwing underside with marked small black spots in spaces Sc R₁ to Cu₁, uncus in dorsal view with a small prong on the inside of each arm and valvae symmetrical; and from luanchuanensis by forewing with cell spots totally fused and only two spots in apex; hindwing upperside without orange spots centrally, underside with small black spots in subapical area. Male genitalia with gnathos fused distally, foot-stalks symmetrical.