In this paper, 357 female students in soochow university which are 18 to 26 years old were selected as subjects. Front, back and side photos are taken by using digital camera, and then photo manipulation was done to amplify the contrast between the human body and background. The width and thickness of human characteristic positions were measured by COREDRAW software. Meanwhile, the girth of each position was got by manual measurement, and the width and thickness of human characteristic positions were extracted by MATLAB. Finally the girth, width and thickness were analyzed by SPSS to obtain the girth calculative rules, and the error analysis was done to verify the veracity. The result showed that the regression fitting was feasible and accurate.