Abstract: Within the dimensions of subjects, origins, contents, consequences, responses of public hot events, dividing related factors into status differences, multivariate conflicts, unpredictability, major damages and improper responses, the article analyzed the emergence of heat sources in specific events. Data of “List of the heat of public opinion of hot events” on People Website were used as materials. The results indicated that heat sources are an important reason why events turn into hotspots of public opinion, but not every event has the entire heat source; there is not a direct connection between the heat of public opinion and the quantity of heat source factors. Events turning into hotspots of public opinion are associated with the strength of heat source factors; and there are differences at heat source between different kinds of events. Cognition and analysis of heat source can provide instruction for the government to control and guide hot events of public opinion.