Abstract: This paper used financial media types to describe the discourse, and made an empirical research on how news discourse would influence investors' stock trading behavior and stock price via using CSI 300 Index. The research results show, for the government background financial media, professional financial media and Internet financial media, there are significant differences in the number of reports, information conciseness, emotional scores and emotional divergences among these three types of media coverage, which produce different effects on stock price fluctuation changes through investors' attention and investors' sentiment. This paper is of great significance to standardizing the development of news industry and to guiding investors to invest rationally.