On the basis of grid digital elevation data, the digital river network and spatial topological relation were generated over the area controlled by the Xiashan Hydrometry Station in the Ganjiang River Basin, including 21 198 grid cells at a resolution of 30s. The grid-based precipitation and evaporation data obtained from the nearest stations were applied to calculate the hydrograph at Xiashan Station. In daily mode, the duration from 1978 to 1985 was taken as the calibration period for the Xin ’anjiang Model with the objective function of minimal runoff error, the duration from 1986 to 1987 as the verification period of model parameters. In flood event-based mode, the 16 flood hydrographs were used for parameters calibration, and the other 6 hydrographs for model verification, by taking runoff depth, flood peak discharge, peak timing and model efficiency coefficient as the objective functions. The computational results show that 88% of the flood events for calibration are acceptable in the event-based mode, and other 6 flood events for verification are valid. Therefore, the grid-based Xin’anjiang model performs well as applied in the study catchment.