Recently, the number of female web users is increasing very rapidly, and understanding their consumer behavior on the cyber space becomes an important issue. The present study examines if there are gender differences in Novak, Hoffman and Yung's causal model of flow(1998) and Kim's model of the relationship between flow experience and purchase behavior on EC(1999). On-Line research is performed for approximately 1990 web users. The results of the analysis of covariance structure support both of the models for males as well as females, demonstrating that flow experience relates to purchase intention through EC. However, the path from 'involvement' variable to 'skill' variable is not significant, which is related to the discrepancies of computer-use career and ability between males and females. The theoretical as well as practical implications of these findinfs, the limitations of this study, and the direction of future research are discussed.