Baxigai Formation and Bashijiqike Formation are main reservoirs of Cretaceous in the north edge of Kuche Depression. In Cretaceous Period there are different types of delta sedimentary systems developed in different stages of the basin evolution. The main sedimentary systems include lacus-lacustrine delta sedimentary systems in Baxigai Period, fan-delta sedimentary systems in early Bashijiqike Period and lacus-braid-delta sedimentary systems in mid-late Bashijiqike Period. Vertically, the lower sandstone section of Baxigai Formation is of aggradational sequence in general, and the upper mudstone section shows as progradational sequence. The III section at the lower part of Bashijiqike Formation shows the evolution from progradational to aggradational sequence, and the II-I sections of the mid-up part shows as a coarsening up sequence as a whole. Laterally, the sedimentary facies in the north edge of Kuche Depression spread from east to west as a whole, and the sedimentary facies varies obviously from south to north bides. Based on research of the sedimentary facies, integrated with the analysis of tectonic movement and diagenesis, we believe that the sandstone of braided delta front is quality reservoir, and the reservoir around well KL2 is the best, and become worse both westward to well KL1 and eastward to well KL3.