Abstract: Through sedimentary facies characteristics study,the research finds that Chang 4 + 5 and Chang 6 oil-bearing lay-ers of Chuan 46 block in Chuankou oilfield displays unicline form in western-leaning,and the deposition is controlled by structural features and the structural features affect or reflect the deposition in a large degree as well. Through electrofa-cies recognition,the main sedimentary facies of oil-bearing layers have been confirmed: delta front and plain; the major sedimentary microfacies are: underwater distributary chan-nel,channel sand,interdistributary bay,crevasse splay and etc. Therefore,the distribution characteristics and evolution laws in the plane and the vertical direction have been con-trolled.