In theory,there is a close interactive relationship between urbanization and motorization. This paper investigates the interactive relationship between urbanization and motorization in China after its reform and opening-up by using the urbanization and motorization data during the period 1985 – 2010. The research fi nds that during the period 1985 – 2000,there indeed was a long-run stable interactive relationship between urbanization and motorization in China. It proves that motorization has a time lagged impact on urbanization,whereas urbanization alone has less effect on motorization growth than the infl uence of motorization growth on the rapid growth of urbanization.