Half of the 7 billion global populations are living in cities. 2.3 billion People will crowd into cities in the next 40 years. The rapid urbanization will expose cities to the threat of natural disasters. For the first time ECOSOC of UN has deliberated natural disasters threatening global cities in the 2011 Revision of the World Urbanization Prospects ,particularly the systematic assessment of the hazard to cities with more than 1 million populations.This paper sorts out different vulnerability assessment indicators. Principles and methods of dealing with nature disasters proposed by UNISDR,then deems that response must be within the framework of sustainable development.Cities in developing countries responding to natural disasters must adhere to three points:abandoning total wrong measures;raising funds from a variety of channels and actively carrying out humanitarian work. As for China's cities,it is urgent to build the overall strategy and carry out appropriate technical measures, strategy and carrying out appropriate technical measures. <<