长江三角洲从整体上看其投资环境水平虽处于全国前列，但区内各部分，如上海与杭嘉湖、宁镇扬、苏锡常通、甬绍舟等地市之间都还存在很大差异。针对这种地域差异性，确定了长江三角洲县域投资环境分类评价的指标体系和数学模型，将三角洲地区７１个县市划分为四种类型，并根据各类型的环境特征对其投资导向进行了探讨。 Although the level of its investment environment in the Yangtze River Delta is at the forefront of the overall national economy, there are still quite a few differences between various parts of the region, such as Shanghai, Hangzhou-Jiaxing-Huzhou, Ningzhenyang, Suzhou-Wuxi-Changzhou and Ningbo-Shaogzhou. In view of this regional difference, the index system and mathematical model for the classification and evaluation of investment environment in the Yangtze River Delta are determined. The 71 counties and cities in the delta are divided into four types, and their investment orientation is discussed according to various types of environmental characteristics .