Magma mixing has been recognized by bulk geochemistry for a long time, but without direct mineralogical evidence presented. In this regard, we have carried out a systematic mineralogical study on the clinopyroxene (Cpx) both occur as phenocryst and matrix in the thin-bedded basaltic trachyandesite interlayers in the Shangshu Formation at Wanyao Township, Jiangshan city in Zhejiang Province, in order to reveal its petrogenesis, tectonic setting and magmatic dynamic processes, and provide new evidence for the evolution of Proterozoic magmatic structure in the Jiangshan area. The clinopyroxene phenocrysts develop a core-mantle-rim texture, and the mantle and rim contain many mineral inclusions such as ilmenite, clinopyroxene and plagioclase, indicating that it has experienced complex process of magmatic evolution. Both the phenocryst and matrix the clinopyroxene are augite, the composition of phenocryst, from core through mantle to rim, show regular changes, i.e., the contents of CaO and MgO increased, and the contents of Al2O3, Na2O, and K2O gradually decreased, but the matrix Cpx has lower Ti, Al and Na content and similar to the edge composition of the phenocryst. In-situ trace element composition of the zoned phenocrystal show similar characteristics from core through mantle to rim, showing the enrichment in Th, La, Nd and Ta and the depletion of Nb, K, Ti and Pb. Calculated temperature and pressure results show that the formation temperature of phenocrysts and matrix is relatively low (1040.3~1122.3℃), but the crystallization depth of phenocrysts is deep (10~12 km), while the crystallization depth of mantle and edge rich in mineral inclusions is shallow (3~6 km), and the mantle has the lowest ∑REE contents (44.33×10^-6~63.66×10^-6) and without a negative Eu anomaly (Eu/Eu*=0.98~1.12). The composition and core-mantle-rim texture of clinopyroxene phenocrysts in the Shangshu Formation indicate the existence of magma mixing, which maybe the result of the mixing of basic and acidic magmas at the depth of middle-upper crust. The formation of Jiangshan basaltic trachyandesite may be related to the extension of the paleo-island arc after the collision and splicing of the Cathaysian and Yangtze continental blocks in the late Neoproterozoic.