Abstract: The Naot-Rodi algebraic turbulence stress model (N-R model) and the hybrid finite analytic method with staged grid are used to predict the behavior of 3-D overbank flow.In order to get the stable convergence solutions,the two kind measures are taken.The first is to use the correctly derivative scheme in non-uniform grid.The second is to use the multi-block matching method.Numerical tests are carried out for an open channel flow with compound section.The detailed results of main velocity contours,second flow distribution in cross section,lateral velocity distribution for relative water depth with 0.46, depth variation of proportions of flow in channel and floodplams are compared with the experimental data.Some quite reasonable results are obtained.It can be shown that the N-R rmdel with hybridfinite analytic method can be used to predict the relationship between water level and discharges for overbank flow.