以吉林西部为对象，利用主成分分析和熵权法探讨其生态承载力演变规律与驱动因素。通过主成分分析，从影响生态承载力的指标中提取了3个主成分：C₁表征系统发展状态，C₂表征系统经济效率，C₃表征水资源供给。以C₁、C₂和C₃构建承载力评价体系，利用熵权法分层次对各指标赋予权重得到生态承载力综合指数ECC。结果表明：1995-2004年吉林西部ECC从0.316上升到0.527，但ECC波动性较强。系统经济效率的上升是ECC提高的主要原因，水资源供给能力是ECC波动的首要影响因素，也是ECC提高的主要限制因素。吉林西部所承载人口和经济水平上升的同时也造成了资源的大量消耗和生态系统严重退化，资源环境指数发展缓慢，这将会对未来人口经济的发展具有较大的限制作用。

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.