By analyzing the extreme weather events occurred in main cities of Chi na in 2007, and comparing with the developing process of city building, it is e xpatiated that the threaten of meteorological disasters to the safe running of c ity is more and more serious. Now some violent weather phenomena often occurred and capability of enduring disasters of big cities is weaker and weaker becaus e the extreme rainfall events are increasing day by day. The developing speed o f city and the population density in big cities are high, which leads to socal led “cityhot islanddomino effect" more obvious than before. The scientific q uestions to be solved in analyzing the factors and results of disasters are present ed, such as building layout of city and response management system for urgent w eather event. Meanwhile, the suggestion for makingdecision about how to preven t and reduce disasters in big city is brought forward.