Abstract: A feasible research on cushion pool of Nuozhadu Hydro power Station with lining slope but without bottom protection is carried out by a hydraulic model with a scale 1∶100. With bottom protection, the stability and possible destructive zone of bottom and slope of the cushion pool are studied according to time - average pressure, fluctuating pressure and uplift force. With lining slope but without bottom protection, the scouring shape and maximum scouring depth of the pool bottom and toe are measured under various working cases, damage causes of the toe are analyzed, and an optimized scheme, i.e., appropriately enlarging width of the cushion pool and adding a bedplate protection, is proposed. The test results show that this scheme is feasible. 