The purpose of this study is to test the Kuznets Hypothesis on the relationship between environmental pollution and economic growth by using the panel data. The major results of the study can be summarized threefold as follows. First, previous studies can pose the risk of spurious regression because of the nature of non-stationery of the data used. Second, the result of the co-integration test indicates that the emission of CO_2 and per capita income are co-integrated. Finally, according to the results of OLS and DOLS estimation, the turning point in this study is set in far higher level of per capita income compared with those in previous studies.