West Jilin province is a typical area of the frangible agro-pastoral ecotone in northern China, where the sustainable development was heavily restricted by both the natural and socio-economic factors. Principal Component Analysis (PCA) and Entropy methods were used to evaluate the evolution of the ecological carrying capacity (ECC) of West Jilin province from 1995-2004. Through PCA, 3 principal components were obtained from all the indicators to represent 3 main factors of ECC: C₁ Development level of ecosystem, C₂ Economic efficiency and C₃ Water resource abundant. Entropy method was utilized to calculate the weight of each component and corresponding indicators and then got the comprehensive index ECC. The results indicated that: ECC of West Jilin province has been increasing with obvious fluctuation in the past 10 years, and the economic efficiency rise contributed most to the ECC increase while the water resource was the main driving force of ECC fluctuation. As a consequence, the ECC increase led more resource requirement and sever ecosystem degradation of West Jilin province, thus the resource-environment developed slowly from 1995-2004. The resource-environment, especially the water resource, will lead great restriction to the ECC in future if no effective countermeasures to improve it.