To provide a parakeratosis inhibitor agent, pore-shrinking agent, or skin roughness preventing/ameliorating agent comprising one or two or more compounds selected from a group consisting of aminosulfuric acid derivatives and the salts thereof as represented by general formula (10)(10), a skin preparation for inhibiting parakeratosis for external use comprising a parakeratosis inhibitor agent, a skin preparation for shrinking pores for external use comprising a pore-shrinking agent and a skin preparation for preventing/ameliorating skin roughness for external use comprising a skin roughness preventing/ameliorating agent.
