Abstract: The lower Cretaceous Xiagou formation of Yinger sag is land facies fault basin featured with multiple source and multiple types of sedimentary facies.In order to provenance and sand body distribution,we applied the light and heavy mineral combination characteristic,the ZTR index of heavy minerals,rock types,sand rock content and seismic analysis methods to analyze northwest provenance.The results show that:lower Cretaceous source of Xiagou formation is obviously zoned,which developed in 7 sources,mainly in north Tianquansi convex and west Wenshushan convex,the source and distribution of sand body are in good corresponding relation,which fundamentally determines the distribution pattern of the early Cretaceous deposition system.