Abstract: The relationships between hydraulic property parameters(flow regime,flow velocity,mean depth and friction factor)and discharge,slope gradient were simulated in a hydraulic flume(5 m×0.4 m×0.4 m). The unit discharge varied from 0.625×10^-3/(s·m) to 12.5×10^-3m³/(s·m),and the slope gradients varied from 5° to 25°. The results indicated that there is deeply relationship between the flow regime and the flow depth. The flow mean velocity,depth and the Darcy-Weisbach friction factor(f)are mainly controlled by the discharge,and can be well simulated by a simple power function of unit discharge and slope gradient. The determination coefficient are 0.98,0.97 and 0.95 respectively1 When the slope gradient is cancelled,the determination coefficients only decrease 7%,16% and 3%. When the Reynolds number increases,the Darcy 2Weisbach friction factor decreases as fine power function1 The influence of slope gradient on f depends on the discharge.