Tile purposes of this study were to find out any significant relations among body image, needs for body modification, self concept, and some selected clothing behaviors of two age group females using social comparison theory as the research background. The sampling method was a convenient sampling, and the subjects were 56 females aged from 20 to 24 years and 54 females aged from 40 to 49 years. The quasi-experiment and survey were conducted from May 1 to June 30, 2002. The results of tile study were as follows. First, the perceptual body image is more important than measured body size and ideal body size in body image. Apart from measurement instrument, people who perceived slim had higher self concept, exhibition and conformity of clothing. Second, there were significant differences between the two age groups(twenties and forties) in needs for plastic modification, self concepts and clothing behaviors. The younger age group exhibited higher need for modification than the older age group and the younger group also showed higher self concept, higher interests in clothing and fashion, more exhibition tendency and conformity to clothing.