The influences of Magma intrusion activity on the clastic rocks include the magma upwarp activity, the baked activity and the hydrothermal activity. Ascending of magma resulted in the fractures in overlying rocks, whereas baking is responsible for various metamorphisms of the country rocks (clastic rock), i.e., mudstone was metamorphosed into slate. Lowgrade metamorphic slates are often effective caprocks, and highly metamorphized slates are an effective reservoir because of its welldevelopped fracture system. The local geothermal gradient abnormity was derived from magma intrusion and volcanic activity, which often arouses a series of changes around the clastic rocks. Magma intrusion accelerated the thermal evolution course of source rocks. Organic acid, carbon dioxide and hydrocarbon were propitious to preserve the primary pores and produce secondary pores in surrounding clastic rocks. Fe2+ and Mg2+ derived from basic intrusion rocks and eruption would be propitious to change montmorillonite into chlorite. The results are that the clastic rocks around the igneous rocks are characterized by a high chlorite, poor kaolinite, and higher illite.