Baekcheon watershed, which is mostly consists of rice paddies and fields, is expected to be higher non-point source pollution impacts. The effect of the non-point source pollution appears fairly large in the tributaries because tributaries are within close proximity to pollution sources unlike the mainstream and the flow rate of tributaries is insufficient. The developed model based on Fortran was applied using input data derived by ARC-GIS in order to analysis quantitatively for the direct runoff and the non-point source pollution load. As a result of the application, we found the contribution rate and the reduction rate for non-point source loading according to change of landuse.