Objective：To probe into rule of skin development and aging by extracting corner density and rimae cutis area in skin im－age. Methods：The amplificatory skin images on the middle of inner forearm of healthy people were collected by digital microscope. High technologies of image processing including image segmen－tation and corner detection were applied to extract quantitative data of the two parameters. Skin texture development rules were analyzed by using statistics methods of correlation analysis，variance analysis and regression analysis. Results：The experi－ment data showed that the area of rimae cutis increased with age（male：r=0.950，P=0.000，female：r=0.960，P=0.000）. The density of corner in skin image was decreased with age（male：r=-0.958，P=0.000；female：r=-0.969，P=0.000）. Conclusion：The method of this paper is effective in exploring the skin texture development rule. The research helps to assess the effect of cosmetic objectively and improve cosmetic operations with quantify data. The research also can be applied to forensic aging identification.