Abstract: Based on the 1:50000 regional geological survey in Zhuluke-Boluochi sheet,the basin-controlling structure,sedimentary substances and volcanic rocks in Boluochi Basin are studied.By analyzing the volcanic materials,terrigenous clastic sediments and their sequence,the formation of Boluochi Basin may be divided into three cycles.In each cycle,the sedimentary process begins with volcanic explosion,followed by continental clastic deposition.The polycyclic formation of the basin is quite clear.The basin is in compression stress environment in Middle Jurassic,and extension in Late Jurassic to Early Cretaceous.Simultaneously,the center of the Mesozoic basin transferred from the West(Zhongsanjia-Maozhengou)to East(Maozhengou-Huangdaoyingzi).