Abstract: With the guidance of sedimentology and high resolution sequence stratigraphy, a detailed study on the characteristics of fan delta deposits and cycles of Baodaowan formation in Shichang section in the southern margin of Junggar basin is conducted by means of the outcrop observation and measurement. The nine types of lithofacies and four kinds of typical lithofacies associations developed in the Bad?aowan formation respectively represent the braided channel of fan delta plain, the braided distributary channel of fan delta inner front, the underwater distributary channel of fan delta outer front and the sheet sand of pre?fan delta. The fan delta plain of Badaowan formation is characterized by that the sand bodies in multistage braided channels of fan delta plain are vertically superposed into a thick sand body, in which the thick and fine grained barrier layers are deposited at the bottom and the top. The braided channels with better physical properties are the main reservoir sand bodies. In the outcrop, two long?term base?level cycles are identified, namely LSC1 and LSC2, and the Bad?aowan formation can be subdivided into four medium?term cycles and a number of short?term cycles.On the basis of control factors of the tectonic movement, accommodation and sedimentary provenance, the base?level cycles of Shichang section could be compared with that of Sikeshu River section