Using data from the land purchasing records for the eight elite (Yangban) families in the 17-19th century Korea, this study explains the effects of tax system change on the intensive selling-out phenomenon by the commons. In contrast to previous studies, this research provides evidence for the commons’ land selling-out phenomenon, and explores the role of tax system change in causing this phenomenon in the 17-19th century. Converting various taxes into land tax resulted in higher cost of keeping land for the commons, who sold out eventually to save the costs given low land productivity. Outflows of the commons from farming land had reduced the number of people paying tax, and reduced the Korean governmental revenue fast.