This paper evaluated the socio-economic and eco-environmental benefits of land use during the urban expansion period of Nanjing City from 1990to 2008.Subsequently,their dynamic relationships were discussed based on the theory of co-integration.Methods of improved entropy,error correction model and variance decomposition were employed.Results showed that both of the indicators of socio-economic and eco-environmental benefits were increased and were integrated of order one.There existed an equilibrium relationship between them in long term,whereas things were different in short term.The magnitude of the adjustment from short-term fluctuation to long-term equilibrium was 45.36%.The eco-environmental benefits were the Granger's cause for socio-economic benefits,but the contrary was not true.The eco-environmental benefits were the main driving force that can be used to improve the comprehensive benefit of land use.The proportions of socio-economic and eco-environmental benefits could be represented as 85.27% and 93.89%,respectively,in twenty years later.Therefore,it is necessary to play the important role of eco-environment benefits by taking long-term and short-term strategies completely.On the one hand,the efficiency of environmental pollution management should be improved in the short term.On the other hand,the road of sustainable development should be taken in the long term,through conforming to the system of economic growth mode transformation and vigorously developing the low-carbon economy and green technology.