With the advancement of Internet, electronic commerce has rapidly expanded and considered as a major retail channel. In the early days of the Internet, many studies compared offline and online stores on their price level and dispersion. Since e-commerce is considered matured, we need to see price change behavior in e-commerce rather than comparing it with traditional channels. Thus, this study investigated the trend of price changes in e-commerce. The data that was gathered from a price comparison site also contained six product categories. The decrease in minimum and average price was identified and the increase in maximum price was also identified. The critical factors in the increase of maximum price are number of sellers (positive effect) and the time span after a product was released (negative effect). The differences in price changes between product categories were also investigated.