The vulnerability of eco-environments in the Yangtze River Delta was assessed in an integrated manner with remote sensing data and geographic information system software combined with spatial principal component analysis. Evaluation index systems were generated, and an analytic hierarchy process (AHP) was used to determine evaluation factor weightings. The causes of vulnerability were analyzed. The results show that the Taihu Lake drainage basin and the western and the middle parts of Zhejiang Province, which are located in the middle part of the Yangtze River Delta, are the most extremely and seriously vulnerable regions. These regions account for 20.10％ of the whole study area. The lightly and moderately vulnerable areas were scattered throughout the entire study area, and accounted for 55.25％ of the study area. The slightly vulnerable areas were mainly located in the north of Jiangsu Province and in the east of Zhejiang Province, and accounted for 24. 65％ of the study area. On the whole, the eco-environment in most areas of the Yangtze River Delta is lightly and moderately vulnerable. The natural factors which influence the eco-environmental vulnerability of the Yangtze River Deltaare: days of temperature not less than 35 °C , drought and flood frequency, elevation, yearly integrated NDVI, landscape diversity index, and soil erosion intensity. The human factors which influence the eco-environmental vulnerability are: per capita arable land area, per capita water resources, discharge of waste water per capita, per capita exhaust emissions,amount of chemical fertilizer, land use change, waste utilization product value, population density, GDP, etc. The extremely and seriously vulnerable regions show the characteristics of high frequency of natural disasters, lack of resources, high pollution level, serious soil erosion and low biodiversity.%使用空间主成分分析法构建评价指标体系,采用层次分析法确定指标权重,结合遥感数据与地理信息系统软件,对长江三角洲生态环境脆弱性进行了综合评价,并对脆弱性成因进行了分析.结果表明,长江三角洲生态环境极度和重度脆弱区主要分布在其中部的太湖流域和浙江中西部,占整个研究区的20.10%;轻度和中度脆弱区遍布于整个研究区,占55.25%;微度脆弱区主要分布在江苏北部和浙江东部,占24.65%.总体来看,长江三角洲大部分区域的生态环境属轻度和中度脆弱.影响长江三角洲生态环境脆弱性的自然因素有≥35 ℃日数、旱涝分布、海拔高度、归一化植被指数(NDVI)年累加值、景观多样性指数和土壤侵蚀强度;人为因素有人均耕地面积、人均水资源、人均废水排放量、人均废气排放量、化肥施用强度、土地利用变化、"三废"综合利用产品产值、人口密度和GDP.极度和重度脆弱区生态环境的主要特征是自然灾害发生频率大、资源匮乏、污染强度大、土壤侵蚀严重和生物多样性低.
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