Efficient distribution for emergency logistics is vital to alleviate the disaster impact after the occurrence of earthquake. This paper studies the distribution priority of different rescue resource. Using Risk Priority Number (RPN) methodology,a dynamic model for identifying the relief-demand urgency is built. In the new RPN model, the parameters are redefined and a set of weights are assigned to them. The calculation algorithm is presented. In the case study, the RPN is calculated to rank the order of priority of resource allocation and distribution for the affected areas. The simulation results indicate that the proposed method is effective and applicable.