Abstract: The Toutunhe formation in Baijiahai swell in Junggar basin is a typical fluvial-flood plain deposit. Its fluvial changes and sandbody distribution have been lack of in?depth studies, which restricts the oil and gas exploration and development of it. This paper clarifies the paleo?fluvial types and sedimentary sequences of Toutunhe formation by observation of the outcrops, presents corresponding sedimentary model; integrating with the well logging data and seismic attributes, it studies the identification characteristics, sedimentary evolution and sandbody distribution regularity of this fluvial deposit. The results show that such a distribution and evolution is mainly controlled by topographic slope and sediment supply. In the lateral expansion direction of the channels, the fluvial deposit is mainly controlled by topographic slope; while along the provenance direction, the sediment supply becomes major controlling factor, The fluvial sand bodies are predominately distributed in the east and west parts of the study area and major distribution of sandbody direction is from north to south