Direct solar Radiation (DSR) is the key component of the global radiation reaching the Earth. The DSR quantity reaching the rugged terrain is the compositive action results of sky and terrain factors. Based on a distributed model, with DEM data of 1：250 000 scale and routine meteorological data as input, normals of monthly and annual DSR quantity with the resolution of 100 m×100 m over rugged terrains of Zhejiang province were simulated and their spatial distribution characteristics were analyzed. Surface and atmospheric factors were all considered in the used model. The results suggest that DSR in Zhejiang province reaches the highest quantity in July and August and the lowest in January and February; the normals of annual DSR quantity is 2 083 MJ/m2; the influences of local topographic factors on DSR are changing with seasons and are more obvious in cold seasons that have a lower solar elevation angle.