The effects of the shape of the cross-section on flow resistance in open channels has received considerable attention from hydraulic engineers for many years. Many investigators have tried to introduce parameters to represent the cross-section shape effect but their results have been inconclusive. Some of the techniques previously used to deal with this problem are reviewed and their shortcomings are discussed. A new method for dealing with shape effect is developed in this paper from considerations of dimensional analysis and using the experimental data of TRACY and LESTER and of SHIH and GRIGG. This method, which is referred to as KAZEMIPOUR'S method, employs new parameters more representative of the effect of cross-sectional shape on flow resistance in open channels than those previously used and offers solutions more rational than those previously proposed.