Abstract: The normal depth plays an important role in hydraulic calculation.To a compound channel,when water in a main channel flows in an out of bank condition and onto the adjoining flood plain,it results in great error if the normal depthiscal culated by the Manning equation.All kinds of methods predicting the normal depth in compound channels are systemically summarized in this paper.In all the methods,the normal depth is solved by the dichotomy method and compared with different series of experimental data from Engineering Research Council Flood Channel Facility.By comparison,it is found that the calculation precision is high with the methods considering momentum exchange between the main channel and the floodplain.According to the order from high precision to low,they are,in turn,the channel coherence method,the Liu Peiqing‘s method,the cross sectional inclined division method,the momentum transfer method,the Xie Han-xiang's method,and the superposing cross section method.By analyzing the advanteges and disadvantages of the methods mentioned above,it is pointed out that the channel coherence method is a good method in calculating the normal depth in natural rivers with compound cross section.