Heigouxia volcanic rocks, located in Lüeyang area, Mianlüe tectonic zone, South Qinling Orogen, are a combination of tholeiite basalt and little calcalkaline andesite, and their LAICPMS zircon UPb geochronological and petrogeochemical studies are determined in this paper. The results show that Zircon UPb age determined using laser ablationinductively coupled plasmamass spectrometry from Heigouxia andesitic sample is 807±13Ma(MSWD=3.6, n=14), indicating the crystallizedage of the Heigouxia volcanic rocks in Middle Neoproterozoic. Heigouxia basaltic rocks possess the features of NMORB on the whole, such as leftleaning REE patterns, Narich, and Ppoor. The region of basaltic magma was reformed by recycled material. Heigouxia andesitic rocks have higher SiO2 concentrations (43.54％~54.51％) and instable varieties of Na2O and K2O. On account of the geochemical characteristics such as negative anomaly of Nb, Ta, P, Ti and La/Yb, Sc/Ni, Th/Yb ratios, Heigouxia andesitic rocks are deemed as the remnants of ancient continental marginal arc. Relatively high Mg# and large varieties of Cr, Ni, and A/CNK (0.58~1.62) indicate the crust—mantle mixing model of the andesitic rocks. Above all, Heigouxia volcanic rocks are considered as the product of Neoproterozoic Mianlüe Oecan and its subduction rather than Late Paleozoic bimodal volcanic rocks. Combined with regional geological data, the authors consider that there existed Neoproterozoic arc—basin system in Mianlüe area, and the north trend subduction did not quit until about ~800Ma. This process was likely to be response to the amalgamation of Rodinia supercontinent.