This paper examines crisis science communication behaviour of Chinese scientists during the early time of Covid19 pandemic in China. A conceptual model of the Theory of Planned Behaviour is constructed to examine the crisis science communication intention of Chinese scientists during the early stage of the pandemic. The results of the model show that the conventional variables of the theory of planned behaviour model such as attitude towards science communication,subjective norms,perceived behavioural control,and moral norms all have positive effect on scientists’ intention to engage in science communication. A variable proposed in a Chinese specific contextperceived institutional supportpositively can influnece scientists’ attitude towards science communication and perceived behavioural benifits. However,neither perceived institutional support nor perceived behavioural benefits positively influence scientists’ intention of crisis science communication. These empirical findings show the strong organizational characteristics of Chinese scientists in the process of science communication and their high sense of social responsibility in the crisis situation; at the same time,this study also reveals the shift from “science communication” to “knowledge expression” and explains the value of this shift in subsequent studies.