This thesis reviews relationships between economic growth and water pollution in South Korea using the Environmental Kuznets Curve (EKC). Both national perspective (pooled data) and regional perspective (each river) are used to reveal the EKC theory. Given that the small sample covers four rivers and the period of 1985-2009, Fixed-effects model with a robust standard error is chosen for removing econometric problems. Empirical results demonstrate that the EKC theory explains water quality change in South Korea, depending on the types of water pollutants and their generated regional characteristics. The Han River does not show inverted-U shapes for BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand), but the Geum River (BOD), the Yeongsan River (BOD and COD), and the Nackdong River (COD) show inverted-U shapes. At the national perspective, BOD and COD might show inverted-U shapes; therefore, the EKC relationship cannot always be generalized between economic growth and environmental pollution.