Surface hydrology has changed significantly in the marsh rivers of the Sanjiang Plain which plays an important role in guaranteeing the security of the China′s food supply. The soil and water assessment tool (SWAT) was used to simulate discharge of the upper Naolihe River watershed, the satisfying simulation results indicating the applicability of the model to marshy rivers. Because of no or sparse hydro-meteoro - logical data in a number of basins of marshy rivers, the calibrated SWAT model was applied to the Qixinghe River watershed according to mod - el parameters transplantation method. The Nash-Sutcliffe model efficiency (NS), coefficient of determination (R2 ) and Percent bias (PBIAS) for annual flow were 0.92, 0.96, -0.05 for calibration periods and 0.96, 0.97, -0.18 for validation periods, respectively, suggesting that the SWAT model could be applied to this basin.