In recent years, new media like microblog plays a more and more important role in public information sharing and communication.The emergence of new media on the internet not only creates a new mode of interpersonal communication, but also brings significant impact and change to information provision & communication and approaches, routes& timeliness of information acquisition on the capital market.Through hand collecting and detailed reading of information of listed companies published on Sina microblog, this paper investigates microblog information disclosure of listed companies for the first time.Results show that the content of information disclosed by listed companies through microblog is very extensive, and the most content of information disclosed is operation information, especially sales contracts, awards and R&D & innovation.Besides, about 84% of the information disclosed by listed companies through microblog is not published through official announcements.Furthermore, it also examines the effects of the characteristics of listed companies on their willingness to register in Sina microblog and the number of released information.Results show that companies with high-level corporate governance more tend to register in Sina microblog and release more information closely related to the companies, especially information that is not published through official announcements and strategy-based information about operation activities.Information disclosure through new media on the internet as an emerging field is worthy of deep study on issues like how information disclosure through new media on the internet affects listed companies and whether it can reduce the stock price synchronicity and the financing costs.