By using the observation data from only three solar radiation stations in Guizhou Province, comparison is made between the calculation errors from two methods (sunlight percentage and nationwide universal formula). The results indicate that the absolute error values of the monthly and annual mean solar radiation calculated by the sunlight percentage method are less then 10%, and the sunlight percentage model is better than the universal method obviously. Since solar radiation increases with increasing altitude, the model is set up according to the altitude of each station by means of the sunlight percentage method. From the related data from 1971 to 2000, the solar radiation is calculated, and the distributional characteristic are analyzed.