An ecological early-warning model to evaluae the process of urbanization was set up based on fuzzy matter element theory. The alarm signals were divided into five grades, namely, non-alert, light alert, middle alert, heavy alert and giant alert. Taking Hexi Corridor in Gansu Province as an example, we set up an index system of the ecological early-warning in the process of urbanization and established the early warning standards, limits, lights and degrees. The results showed that the order of ecological early warning exponent of Hexi Corridor and the five cities is shown as the following: Zhangye, Wuwei, Jinchang, Hexi Corridor, Jiayuguan and Jiuquan. The boom exponents of ecological water proportion, vegetation coverage, environmental protection costs per capita and output value of industrial SO2 emissions per 10 000 Chinese yuan in Hexi Corridor are the highest. It shows that these exponents are in a heavy alert state. The boom exponents of urban industrial land ration, urban residential land ration, output value of industrial wastewater and dust emissions per 10 000 yuan in Hexi Corridor are the lowest. These exponents are in a light alert state. And the other exponents are in a middle alert state. Clearly, in relation to land resources and environmental factors, water resources and ecological conditions have played a strong role in the shackles of the urbanization in Hexi Corridor.