With the acceleration of urbanization,a series of ecological problems such as population expansion,traffic congestion,environmental damage,air pollution,and energy shortage seriously restrict the sustainable development of city,and influence urban ecological security.Focused on urban ecological security problems,we took Zhengzhou as an example and adopted the matter-element analysis and entropy method to establish a model of ecological city security entropy and matter-element.First,the index data of Zhengzhou between 2001 and 2004 were processed and calculated by entropy weight method.Second,urban ecological security of Zhengzhou city in 2001 was comprehensive evaluated by matter-element analysis.The results showed that the ecological security of Zhengzhou in 2001was in unsafe condition.The evaluation results are objective and scientific,which can not only provide an efficient evaluation method for solving the urban ecological security,but also be able to understand the development of the city's status to provide a basis for working out the next development strategy.