With the development of science and technology and the progress of the society，health risk is becoming the main factor influencing the people longevity and health life. As the important channels of health risk communication，including genetically modified food information communication，new media shoulders the great mission.

To explore the role of new media in health communication，this article selects SinaWeiboas the research objects representing new media. By the content analysis of 189 microblogs regarding the genetically modified food information released by authenticated media IDs in 2015，this study found the characteristics of and relations between 5 categories of news sources，report angles，uncertainty presentation formats，emotion presences and news frames，as well as the three roles of “science popularizationbulletin board”，“risk filter” and “guide of emotion” based on the research achievements.