To satisfy the requirements of applications in large scale network, the network layer needs to provide corresponding support. Great efforts have been made to provide services over the Internet which is developing rapidly. In this paper, we propose a new hierarchical routing model - Network Tree Model, which can solve the best effort routing effectively and efficiently in large scale network. It achieves a sharp reduction in communication complexity and routing table scale with a high routing accuracy. Simulation results show that the proposed model and algorithm obtains high performance in traffic for convergence and routing accuracy as expected.