Upstream of Chungju Dam watershed measured to applicability of the Batter Assessment Science Integrating point and Non-point Sources (BASINS 3.1)/ Window interface to Hydrological Simulation Program-FORTRAN (WinHSPF). Water flow calibration was performed using monitoring data from 2004 to 2005 and verification was performed 2005. Water quality (water temperature, DO, BOD, total nitrogen and total phosphorus) was calibrated from 2000 to 2005 and verificated 2006. Calibration results were reasonably reflected simulated and observed data over total simulation period. But TN and TP was some period look out of the observed data. Therefore, It's need to calibrated for more profit parameter. The estimated of pollutant load for average annual BOD, TN and TP was 6,639,663 kg yr^-1, 13,414,389 kg yr^-1 and 228,237 kg yr^-1. Non-point source loading contribution was showing great part of total pollutant loading about 86.5～95.2%.