Abstract: The dimensions and the shapes represent the major role for the efficiency of stilling basin. The Sant Anthony Falls (SAF) type basin was constructed in the University of Minnesota to be used in various structures like canal structures, outlet works and spillways. Although, this type of stilling basin used for a wide range of discharges and Froude number compared to other types of stilling basins but has a deficit of hydraulic stability in large discharges, mildly high cost and a powerful of efficiency at high discharges. This study presented flume experiments to improve the efficiency of the SAF type stilling basin. Twelve new shapes of stilling basin were hydraulically designed and experimentally implemented in the laboratory and compared with the standard shape. The results showed that all the new designed shapes were more hydraulically stable with more efficiency and with low cost compared to the standard one. The results also showed that when doubling the height of baffle pier and decreasing the length of floor by 20%, the efficiency increased to 73% using the shape and dimensions of model #5 which is more efficient, more hydraulic stable and more economically. Moreover, by increasing the distance between baffle pier and chute block and the distance between first and second row of baffle pier, the efficiency of stilling basin was improved at low discharge and decreased at high discharge.