Basically, to evaluate the operational performances of online auction is according to seller¡¦s transaction and investment in the auction website. Thus, how to maintain good relationship with the existing seller switching and attract new seller is the most attention and major care for auction service provider. However, there were few prior researches focused on the topic of online auction switching and examined from real case. In this study, we tried to develop a measuring model and explore the factors that relate to auction seller¡¦s switching. In July 2006, Yahoo! Kimo auction, the largest auction website in Taiwan, announced a new fee scheme which would charge 3 percent transaction handling fee on its sellers from Aug. 10. Many users expressed objection to the new charge scheme. During the same period, Ruten, a new joint venture auction website that combined eBay and Taiwanese portal operator PChome is nearly ready and makes some responding strategic approaches to attract new user. Many sellers of Yahoo! Kimo auction thought to switch auction provider. Base on the background, the study aim to explore auction seller¡¦s switching behavior through switching costs, including procedure costs, financial costs, and relational costs. Moreover, we examined how website quality, fee, anti-lock-in, and anti-switching affect switching intention and behavior. A total of 292 usable questionnaires were gathered through online surveys from auction discussion board and BBS. The data were analyzed by partial least squares (PLS) to test the hypotheses. We find that switching costs, website quality, fee have negative effect on seller¡¦s switching intention. Anti-lock-in and anti-switching have moderating effect in the model. According to the finding, we provide useful guidance for auction seller and auction service provider.