This study is about the reconstruction of fluvial origins based on the grain size distribution of sediment deposits in the western Laizhou Bay,Bohai Sea,China.Thirteen sediment cores were selected to research sediment characteristics using the Sahu discriminant formula,C-M diagram,and Folk method.The results showed: (1) Bounded by the Guangli River estuary,the north sediment was affected by the water and sand flowing from the Yellow River during different periods.The south sediment came from multi-source rivers under the influence of the Xiaoqing River,Mihe River,and other coastal rivers;(2) the deposited sediments were dated by a clear historical record of the branched channel oscillation combined with the characteristics of the diversion channel,erosion,and regression.The subaqueous delta overlapped during several Yellow River channel runs (1897-1904,1929-1934,1938-1947,1947-1953,1976-1996) and the deposited sediment facies changed (the north tidal flat-abandoned subaqueous delta-lateral delta-delta front);(3) the deposited sediment characteristics can be revealed by studying the branched diversions of the Yellow River and coastal multi-rivers of the past one hundred years.