Tongling region is one of the most important non-ferrous metal producers where the formation of Cu-Au deposits has close genetic relations with Mesozoic intrusions. Petrology, Mineralogy and element geochemistry of the Mesozoic intrusive rocks in the Tongling region were systematically investigated in this study. These results show: ①The intrusive rocks can be divided into three rock associations: pyroxene diorite with SiO2≤55%, quartz diorite with SiO2 55%~65%, and granodiorite associations with SiO2≥65%. Their mineral components mainly are andesine, orthoclase, Mg-biotite, and anthophyllite-aluminium anthophyllite series. ②Pyroxene diorite association rocks are mainly shoshonite. They were most probably produced by fractional crystallization primarily derived from an enriched mantle which has the material contribution of ancient subducted ocean crust, and experienced assimilation of a little lower crustal material. ③The quartz diorite and granodiorite association rocks are mainly high potassic calc-alkaline. They possibly resulted from the crustal assimilation and fractional crystallization (AFC). The mixing of mantle-derived and crust-derived magmas might have been the main mechanism throught which quartz diorite and granodiorite associaltion rocks were produced. ④The early Cretaceous period magmatic activity and related metallogenesis is closely related to subduction of the Pacific plate.