通过湖南长沙一次社会调查的数据，运用结构方程模型，分析不同类型的政治讨论 （人际政治讨论和互联网政治讨论）如何在来自不同渠道的公共信息接触和制度化、非 制度化参与之间发挥中介效应。研究发现：人际政治讨论在本地传统媒体的公共信息接 触和制度化政治参与之间发挥遮掩效应，在论坛网站的公共信息接触和制度化政治参与 之间发挥部分中介效应；互联网政治讨论在基于本地传统媒体和论坛网站的公共信息接 触与非制度化政治参与之间发挥完全中介作用；政府自媒体的公共信息接触虽然能够推 动互联网政治讨论和制度化政治参与的发生，但并未对非制度化政治参与产生正向影 响。在公众政治参与意愿增长的背景下，本文的研究结论将给政府的相关制度构建提供 参考。

Basing on a survey in Changsha, by using SEM, This paper analyzed how different types of political discussion played mediated role between public information exposure from different channels and institutional and un-institutional political participation. The study found that： Interpersonal political discussion had played suppressing role between information exposure from traditional media and institutional political participation; Internet political discussion had played mediated role between information exposure from traditional media, website and institutional political participation; Public information exposure from government’s we media had promoted internet discussion and institutional participation, but had not positively impacted institutional political participation. With the growth of political participation, the results can a reference for government to build related institution.