Abstract: This paper gives explanations on the problems which emerged in economically undeveloped regions in the process of sustainable development.Based on these analysis,the approach and indicator system of evaluation were established.The sustainable capacity is evaluated by the data of Xinyang in 1990,1995,2000,2003 and 2005.The result indicates that the sustainable capacity was strengthened in recent years.This approach hold true in evaluation of sustainable capacity of economically undeveloped regions.