The Tongling region of Anhui Province is an important ore district in the famous Lower and Middle Yangtze River Cu-Au-Fe-S metallogenic belt in eastern China. It is also a good example of skarn deposits in the world. Recently, a porphyry Cu-Au deposit associated with pyroxene diorite was discovered in the Shujiadian region. Given that this is the first porphyry deposits found in Tongling ore district, detailed petrological and geochemical work may have significant implications for future exploration. Here we report chronology and element geochemistry studies on Shujiadian pyroxene diorite. The LA-ICP-MS zircon U-Pb dating result reveal the pyroxene diorite from Shujiadian region is 140.5±1.4Ma, which is younger than the granodiorite in Tongling. And the metallogenetic epoch of the Shujiadian pyroxene diorite maybe slightly younger than 140.5Ma. Our results show that the tectonic setting of the Shujiadian pyroxene diorite should be closely related to the paleo-Pacific plate subduction of the continental margin. It may form during the ascend and emplacement processes of magma which is derived from mantle wedge partial melting by subducted oceanic slab fluids metasomatism, during which the mantle source magma might have been transformed with crustal contamination.