The purpose of this study was to provide information on how to improve the current design of infant coveralls through analysis of the design preferences of Korean consumer. In order to compile the information about preferences with the detail design of infant coveralls, a questionnaire was administered to mothers of 241 infants (aged under 36 months) living in Seoul, and analyzed using the SPSS WIN.10.0 program. The results of this study were as follows : 1) Results of buying conditions and design preference of infant coverall : To the question asking what kind of materials they preferred according to the season as material for infant coverall, the respondents preferred cotton hit as the materials for summer, but padding material for winter. The most favored design type were a flat collar, regular bodice type without cutting line, a raglan sleeves, snap front fastener, elastic band cuffs. 2) There is significant difference in preferred material and design among the month of age groups. 3) Analysis of the differences in preferred material and detail design according to gender In preferred material, it seemed as if girl baby group prefer cotton knit material, while boy baby group prefer padding material. There is definite difference in preferred neckline type, girl baby group prefer flat collar, while boy baby group prefer stand collar.