[Objective] To understand knowledge of reaction to climate change risks and related influencing factors among health professionals in Harbin. [Methods] A self-designed questionnaire survey was conducted among 415 health professionals from different medical institutions on knowledge of reacting to climate change risks, including climate change and effects, high temperature and health effects, coping intention, and behavior, with full scores of 16, 22, 4, and 6, respectively. Variance analysis and correlation analysis were performed to explore cognitive factors of reacting to climate change risks. [Results] The average scores on knowledge of reacting to climate change risks of the participants as follows: climate change and effects (11.193.96), high temperature and health effects (15.975.56), coping intention (2.451.22), and behavior (5.56 0.86). Variance analysis results showed different behavior scores among genders (F=5.842, P=0.016), different knowledge of climate change and effects, knowledge of high temperature and health effects, knowledge of behavior, and total scores among different work units (F=9.841, P=0.000; F=8.345, P=0.000; F=6.146, P=0.002; F=3.754, P=0.024), and different knowledge of high temperature and health effects and total scores among different job titles (F=3.327, P=0.037; F=3.444, P=0.033). There were positive correlations of knowledge of climate change and effects with various dimensions of knowledge of high temperature and health effects, coping intention, and knowledge of behavior. In addition, 73.7% of the health workers received the knowledge of climate change and their health effects via internet; 1.45% of the health workers received related knowledge through training or meeting. [Conclusion] The selected health professionals in Harbin show high scores of knowledge of behavior, followed by knowledge of high temperature and health effects, but low scores of climate change and effects as well as coping intension. In addition, job title and work affiliation could affect risk cognition scores.