The mineralogical characteristics of 14 kinds of siliceous raw materials from different regions of China were analyzed by X ray powder diffraction combined with the Rietveld method and scanning electron microscopy. The effects of different kinds siliceous raw materials on the mineral composition and microstructure of clinker were studied. Results show that the content of C3S is decreased and the f CaO content is increased in the clinker resulting from the decrease of simple silicate minerals in the siliceous raw materials, while the quartz content and its crystal size decrease. The minor elements which are associated with the siliceous raw materials have more remarkable effects on the clinker formation than the added ones. K2O can cause decrease of C3S content and increase of its crystal size. For the siliceous raw materials with high silica, the associated MgO in the form of magnesium silicate can better promote the formation of alite.