Abstract: Based on the generic 2D river-network model, a generic numerical model for 2D orbicular river cell is presented by applying the full implicit matrix chase-after method.Accoreding to the modeling method for 1D river-network, the model estabilishes the equations of water level nodes which can be easily used to realize the 2D river-network and 1D-2D coupling rivernetwork by a implicit way.With the numerical results about Yangtze Rive branch of BAGUA island in NANJING, it can be indicated that the model is effective and valuable.