Using Mesoscale Model version 5 (MM5) to calculate the daily precipitation, daily averaged air temperature at the 2.0m heights and daily latent heat, from Feb. 11 to June 30, 2003, of the Heihe mountainous river basin and its near area, with a geographical boundary of 96.786^o～102.284^oE, 37.328^o～40.601^oN and an area of 17×10⁴ km², which was much larger than the area of the Heihe mountainous river basin (10009 km²), the DHWC model was calibrated. The spatial resolution of the MM5 is 3km, the integral timescale is of 3s, and the calculated cycle is about 10d. In the MM5 model, the Grell scheme cumulus parameterization method, the Dudhia option, the explicit moisture scheme (IMPHYS), the cloud-radiation scheme, MRS PBL option, and the modified Oregon State University Land-surface model (OSULSM) were chosen to use. According to the geographical position of the MM5 results and projection transform methods, the MM5 results were projected into Alberts coordinate, which was the coordinate of the DWHC model, and were interpolated into 1 km×1 km, using nearest and cubic methods. The results showed that, when the nearest method was used, the Nash-Sutcliffe equation value of the daily averaged runoff was of 0.79, the balance error was of -0.79%, and the R² value was of 0.81. When the cubic method was used, the Nash-Sutcliffe equation value, the balance error and the R² value was of 0.79,-0.65 % and 0.80, respectively. Though the evaluation criterion values are not very high, the model results are much better than the model results using the data at the meteorological and hydrological stations, with a Nash-Sutcliffe equation value as 0.61. The model results are not very good because of the lack of the detailed soil and vegetation data. The MM5-DWHC model results also showed that the runoff production processes mainly occurred on the soil surface and in the shallow soil layers. The calibration results showed that, the MM5 results were singular to some extent.