This study explores the stages of commercial gentrification using spatial and temporal density changes in non-franchise and franchise coffee shops. The density of coffee shops provides an effective indicator to intuitively explain commercial gentrification processes because it quickly responds to a process of commercial area development. First, this study shows the effectiveness of coffee shop density as the indicator of commercial gentrification using a case study for regions that have experienced commercial gentrification. Second, a cluster analysis is conducted for Seoul based on the relative densities of coffee shops and its change, as well as density ratios. The result effectively explains the spatial and temporal boundaries of areas in commercial gentrification processes. Furthermore, exploring a gentrification process using coffee shop densities offers a more effective tool than that using socio-economic variables by capturing the changes of gentrification stages in neighborhoods with detail temporal units.