Abstract: Volcanic activities and deep faults caused deep fluid activities in the Tarim Basin.Volcanic activities gave birth to deep fluids,and deep faults provided pathways for deep fluids to migrate upwards.In the middle Tarim and Bachu regions,Permian volcanic rocks were widespread.Around well Zhong1 of the middle Tarim region and in faults such as Tumuxiuke,Selibuya,Kangtakumu and Mazhatage of Bachu region,volcanic activities were the most active.During the late Hercynian,the faults Tazhong Ⅰ,Tazhong well 10 and Tazhong Ⅱ in the middle Tarim region and the faults Tumuxiuke,Selibuya,Kangtakumu and Mazhatage in Bachu region were active faults for deep fluid activities.In this way,the middle Tarim and Bachu regions with active deep fluid were favorable for carbonate reservoir corrosion in the lower Paleozoic.