This study was carried out to investigate characteristics of water quality in drainage water from paddy fields district with pumping station in Sumjin river basin. The hydrological monitoring system were operated for water level measurement during 2005∼2006 and temporal variation of water quality constituents such as T-N, T-P, COD, SS were analysed, periodically. The measured values of T-N of the drainage water in non-precipitation were ranged from 0.3 mg/L to 20.3 mg/L(average : 3.1 mg/L) and T-P were ranged 0.035 mg/L to 0.885 mg/L (average : 0.334 mg/L). The values of T-N of the drainage water in precipitation were ranged from 0.3 mg/L to 11.1 mg/L(average : 2.5 mg/L) and T-P were ranged 0.116 mg/L to 0.757 mg/L (average : 0.256 mg/L).