Haerjiawu Formation and Kalagang Formation are continental volcanic rock series and widely developed in Santanghu Basin，Xingjiang. Both Haerjiawu Formation and Kalagang Formation are dominated by intermediateacid volcanic rocks and pyroclastic rocks with local basic volcanic rocks. A comparative study on the rock association and fossil assemblage of Haerjiawu Formation and Kalagang Formation shows that two formations are similar at the forming age of late Carboniferous to early Permian. The Zircon SHRIMP UPb dating of volcanic rocks in Haerjiawu Formation is 3196±98 Ma. Therefore，the volcanic rocks are confined to develop from middle Carboniferous to early Permian. Haerjiawu Formation and Kalagang Formation developed multistage volcanicsedimentary cycles and contain massive volcanic rocks interbedded with pyroclastic rocks，which provides good reservoirs. Dark mudstone in underlying Laoyemiao Formation shows good organic matter with TOC(Total organic carbon)ranges of 071％ ～162％，which is believed to be good hydrocarbon source rock. Hydrocarbon source rock in Laoyemiao Formation，volcanic rocks in Haerjiawu Formation and Kalagang Formation and mudstone in Upper Permian Jijicaozi Group as a sourcereservoircap combination constitute Carboniferous petroleum system and are significant for petroleum exploration.