Abstract: Study on the process of leakage and diffusion induced by earthquake for gas pipeline is carried out. A transient model to calculate leakage volume and diffusion for gas pipeline is established, and relative solution method for the model is presented and risk assessment is made for leakage accident of gas pipeline based on the model. The paper introduces repair and maintenance methods for post-earthquake gas pipeline's leakage accident and presents an entire emergency response system including emergency response procedures, emergency organization system, emergency protection and rescue, emergency program and emergency state termination. It is considered that application of this system can shorten repair and maintenance time and decrease economic loss.