This study establishes key factors on ISM (Internet Shopping Mall) performance in Korea. The four factors are derived from the relevant literature and clarified the concept of ISM characteristics, customer characteristics, ISM evaluation level. and perceived risks by distinguishing between its components and determinants. ISM performance indicators were derived from the previous studios classifying by ISM attitude and ISM usage. We examine on the impact of ISM characteristics and customer characteristics on the ISM evaluation level, then its level and perceived risks on the ISM performance. Hypotheses on four factors of ISM performance were tested for 172 respondents. Results indicate that four factors may partially serve as key predictors on ISM performance. ISM characteristics and customer characteristics was found to be positively influenced on ISM evaluation level, and its level also positively affected on ISM performance while perceived risks negatively affected on ISM performance.