本文分别从扩散模式以及人口特征与扩散的相关性两个层面对2004—2009年中国互联网扩散进行研究。通过近似于PPS抽样入户调查的定点抽样法对2004-2009年重庆地区互联网的使用状况进行数据采集，在此基础上，对该阶段互联网在中国的扩散模式进行研究，得出累积扩散程度在达到“临界数量”后的扩散曲线，与创新扩散的S曲线做对比分析，并探究扩散达到饱和点的时间。通过对互联网使用者人口特征差异的研究，观察扩散在各个群体中的实际状况，以及人口变量对于创新扩散的影响。根据本研究，互联网在我国的扩散尚未呈现饱和趋势；除性别变量外，人口特征变量与互联网扩散具有明显相关性。

This paper studies from the diffusion model and the correlation of demographic characteristics and diffusion the two levels of Internet diffusion according to the 2004-2009 study in China. It works with the PPS sampling through households surveys similarly to fixed-point sampling methods collecting from 2004-2009 of Chongqing Internet usage data. On this basis, in the stage of the proliferation of the Internet in China, it analyzes the pattern of proliferation obtained in the degree of accumulation and gets the diffusion curve which has already reached "critical mass", and it also compares with the diffusion of innovation S-curve , exploring the diffusion time to reach saturation point. By searching for differences in demographic characteristics of Internet users, it observes diffusion in the real situation of various groups and influences of population variables for diffusion of innovation. According to this study, the diffusion of the Internet in China has not yet showed the trend of saturation. Except for gender variables, the demographic characteristic variables significantly associates with the proliferation of the Internet.