中文摘要：

针对中等收入者在现代社会中的重要作用和当前中等收入者研究方法不足的状况，本文基于现代非参数方法中的核密度佑计方法，提出测算中等收入者比重及其变动的新方法，并构建影响中等收入者比重变动的因素动态分解方法。依据居民收入的微观调查数据，本文提出我国中等收入的绝对标准和相对标准，对我国中等收入者的比重及变动情况进行测度，并对影响我国中等收入者比重变动的增长效应、分配效应和水平效应进行分解。在理论和实证研究基础上，得到有政策指导意义的结论。

英文摘要：

Direct to the important role of middle-income people in modern society and the shortage existing in the research methods of middle-income people recently, based on kernel density estimation method in the modern non-parametric methods, this paper proposed a new method of measuring the proportion and movements of middle-income people, and constructed factors dynamic decomposition method of impacting on the changes in the proportion of middle-income people. Based on household income micro data, this paper presented the absolute standard and relative standard of middle-income in China, and measured the proportion and movements of middle-income people, also decomposed growth effects, distribution effects and level effects impacting on the movements of middle-income people. In the theoretical and empirical research, this paper got policy guidance conclusions.