Abstract: Infrastructure construction is the first condition for economic growth, and also the necessary measures for the government to support economic development of the poor regions. Through the research of data envelopment analysis and dynamic spatial lag model in Three Gorges region, this paper discusses the infrastructure investment efficiency and its spatial and time spillover effect. The results demonstrated that the infrastructure investment efficiency overall has improved significantly, but some poor regions' infrastructure investment efficiency may be at a low level equilibrium trap. Infrastructure investment efficiency has significant positive spatial and time spillover effect, which has significant dynamic promotion and spatial coordination. The time spillover effect of infrastructure investment efficiency is more prominent in advantageous region, and the spatial spillover effect of infrastructure investment efficiency is obvious in disadvantageous region. Based on the above conclusions, the key to the further improvement of infrastructure investment efficiency in the Three Gorges region is to break the coordination failure and improve the space allocation.

Key words: Three Gorges region, infrastructure efficiency, spillover effect, dynamic spatial lag model