Abstract: The three typical floods occurring in 1977,1982,1996 in the lower Yellow River from Tiexie to Shunkou with a length of 393.67 km are numerically simulated by the established mathematical model for unsteady sediment transport.The computed results,such as the discharge,water stage,sediment concentra tion,cross sectional erosion and deposition,agree well with the observed data and validate therefore the mathemat ical model.