An overview on the current situation of economic, resource and environmental system in Ordos city shows that there exist some problems, such as wealth gap, irrational industrial structure, pressures on resources exploitation and environmental pollution. The economic development in Ordos depends on coal resource while the exploitation results in water shortage and environmental pollution. In order to realize the sustainable development of ecological economic system, a system dynamics model, which coordinates the subsystems of economy, resources and environment, is constructed and resource utilization efficiency, environmental protection and economical development are considered as systemic parameters to forecast the development trend of Ordos. Then, sustainability of four development modes are compared via setting its control parameters together with a introduced resource-environment loss rate. Finally, we make a conclusion that the Harmonious development-oriented mode makes the GDP growing moderately and the economic losses of resources and environment destruction are under control and the losses decrease gradually, realizing the benign balance between the economic benefit and ecological benefit.