The volume of the Internet shopping mall business has made great increase over the recent years. In this paper, we study the interface of the Internet shopping malls and how it keeps their customers coming back on a regular basis. Chapter 2 shows the trade volume and market status of domestic electronic commerce. Chapter 3 explains some basic terminologies such as usability, user interface. In the latter part of the chapter, we reviewed and analyzed famous overseas/domestic web assessment models, which are Selz & Schubert WA model, The Webby Awards, KMA's Internet Commerce Award and NCA(National Computerization Agency) report. Based on the study results so far, Chapter 4 introduces a new assessment model truly customized on the Internet shopping malls. In Chapter 5, as a means of application of our model to an actual shopping mall, we analyzed the weaknesses and strengths of Interpark based on the standards suggested by the new model.