Objectives：Carboniferous volcanic rocks widely developed at the Western edge of Luliang Uplift in Junggar Basin, due to the complex tectonic background and unclear prototype basin leads to the low degree of oil and gas exploration for a long time. This research studied the residual ocean closure time, the basin prototype and boundary, the basin basement property of the carboniferous at the Western edge of Luliang Uplift in Junggar Basin.  Methods:Based on the seismic data and regional tectonic features analysis, applying volcanic chronology, petrology, and geochemistry analysis, the zircon LAICPMS UPb dating, geochemistry and tectonic environment of the volcanic rock in Yingxi Depression were systematically studied. Results：LAICPMS zircon UPb ages of the Volcanic rocks from Well Ying2 in Yingxi depression were mainly 310.8±2.9Ma. Volcanic rocks have the uniform characteristics with high SiO2 (62%~63%), K2O(5.98%~7.14%), low TiO2(0.5%~0.65%)and Mg#(43.4~58.4), highA/CNK(>1), generally show that this volcanic construction belong to highK calcalkaline acidic rock series formed in Late Carboniferous, having the feature of quasi aluminum. Besides, ΣREE are relatively high，and the rock has slight negative Euanomalies. Trace element diagram standardized by primitive mantle are characterized that LILE (K, Rb, Ba, La) is relatively enriched，while HFSE (Nb、Ta、Ti)depleted. The Geochemical characteristics above indicate Carboniferous rock in the Yingxi depression have the characteristics of the crust and mantle mixed source，which demonstrates that the rocks were the products of oceanic island arc． Conclusions：Luxi area was still in the subductionrelated environment in Late Carboniferous，moreover the subduction direction maybe is northwest to southeast.In late carboniferous epoch，peripheral orogenic belts and basins covering area of west Junggar as a whole was controlled by the west Junggar ocean，joined by limited ocean basin、subduction—accretionary complex、chain island arc belt and arc or backarc basin, the Yingxidepressionisa backarc basin,is to explore, which is a potential favorable zones for exploring selfgenerated and Paleozoic source oil andgas reservoir.