The Huashugou copper deposit is a new type copper deposit discovered under the iron orebodies in the Jingtieshan orefield,western section, North Qilian Mountains, in last 20 years. It is in argument about the tectonic environment and the formation time of the copper deposit. This paper systemically analyzes on main elements, trace elements, rare earth elements and Sr, Nd, Pb isotopes of the diorite porphyrite in the Huashugou deposit, and indicates that the rocks have obvious characteristics of magmas associated with plate subduction. The diorite porphyrite are enriched in Rb, Ba, Th, U, K, Pb, while depleted in Nb, Ta, Ti, and obviously enriched in LREE to HREE. The rocks are enriched in radiated lead , and the value of n(206Pb)/n(204Pb), n(207Pb)/n(204Pb),n(208Pb)/n(204Pb)are 17.72～18.96, 15.497～15.566 and 37.218～38.674 respectively. The number of n（87Sr)/n（86Sr)i, n(143Nd)/n(144Nd)is 0.7053～0.7084, 0.5121～0.5122，reflecting characteristic of EMⅡ. The zircon UPb LAICPMS dating shows that the age of the diorite porphyrite is about 421±24Ma， i.e., the diorite porphyritethe should be formed in Ordovician, the Caledonian time. It is consistent to the formation time of the copper deposit. At the same time, the magmas that produced the diorite porphyrite captured older zircon of Mesoproterozoic Era, whose age is about 1536±370Ma.