In the sense of democracy, it is taxpayers' money that fund Chinese scientific and technological research and development; scientists must do science communication to the public. From the views of the professionalization of science, the ethos of science and responding to risk society, this article explores the relationship between scientists participating science popularization and their responsibility to taxpayers. By investigating the situation of Chinese scientists participating science popularization, it has found that most of them have realized the importance and meaning of science popularization, but lacked an understanding of their responsibility to taxpayers. The ways and forms in which Chinese scientists take part in science popularization have been becoming more diversified. But they are not eager to participate in science popularization, because it is not a part of the evaluations of Chinese scientists. Based on the study, some suggestions have been proposed to cultivate scientists' responsibility to taxpayers and build a mechanic of science popularization evaluation and improve public engagement.