The purpose of this study was to search for the effective mass customized fashion design process based on internet shopping, so that a total of fifteen models of mass customized fashion design processes which are different in the customized degree and in the composition of design elements was proposed in this study, and to compare their efficiencies and appropriateness with those of the existing fashion design process. The data was obtained from a survey of 180 Korean females in their twenties and thirties from Nov 17th to 29th, 2002. The results of this study were summarized as follows: First, more than half of the whole respondents appeared to prefer mass customized products. Therefore, the mass customized design process was considered to be applicable to some sectors in the present domestic clothing market. Second, Respondents generally preferred the designs by mass customized design process model to those by existing fashion design process. However, satisfaction on the designs done by the mass customized design process suggesting only one choice to prosumers was lower than that of existing fashion design process. This result suggested that mass customized fashion design process enabling at least two choices should be presented to prosumers in order to increase their design satisfaction. In addition, the design process models suggesting more that three choices presented higher satisfaction than existing fashion design process.