Abstract In recent years, the rapid development of industry has made air pollution more and more serious, which has had a serious impact on people's lives and health. This phenomenon has also caused widespread concern among scholars. Previous scholars have mostly studied the negative effects of air pollution from different theoretical perspectives. However, few studies have focused on the impact of negative emotions caused by air pollution events. Moreover, there are few studies from an active perspective to explore people's positive response to negative emotions in the air pollution situation. In addition, the existing research lacks in-depth discussions on the internal mechanisms and boundary conditions between emotions and pro-environmental behaviors, and on the internal transformation process of cognition and motivation. The aim of this study is to investigate how negative emotions caused by air pollution affect employees' pro-environmental behaviors in the workplace. Therefore, this study sets out to examine the impact of negative emotions caused by air pollution on the pro-environmental behaviors of employees in the workplace from the intra-individual level, and unveil the serial mediating effects of risk perception and environmental passion. At the same time, this study also intends to uncover the moderating effects of regulatory focus from the inter-individual level. To test our proposed theoretical model, this study has adopted the experience sampling method for data collection. In this study, 68 employees were followed up for 14 days by experience sampling method. We collected data through an online sampling platform - questionnaire star..At the very beginning, we distributed a questionnaire to 78 employees to assess individual demographic characteristics and regulatory focus. A total of 68 data were collected at this stage, with a response rate of 80.95%. Then, the participants completed the daily surveys in 14 working days to evaluate the negative emotions caused by air pollution, risk perception, environmental protection passion and workplace pro-environmental behaviors. Finally, 869 daily survey data from 62 employees were obtained. Mplus software was used to test our theory model. As shown by our results, the fitting index of the whole model was good (χ2=475.06, df=59, CFI=0.97, TLI=0.96, SRMR=0.06, RMSEA=0.10,). These results show that: (1) daily negative emotions caused by air pollution are positively correlated with their daily environmental protection behaviors(β=0.21，p<0.001); (2) risk perception and environmental passion have serial mediating effects between the negative emotions caused by air pollution and pro-environmental behaviors; (3) regulatory focus moderates the impact of daily negative emotions caused by air pollution on daily pro-environmental behaviors. In particular, prevention focus weakens the relationship between them (β=–0.08, p<0.05), while the moderating effect of promotion focus is not significant (β=–0.04, p>0.05). Our findings contribute to current literature in three ways. Firstly, drawing on the affective events theory, this paper discusses the positive coping strategies of employees in the face of air pollution events from an active perspective, which broadens our understanding of how people respond to the negative emotions in the air pollution environment. Secondly, through combining theoretical and empirical analyses, it has been found that there is a close relationship between risk perception (cognition) and environmental passion (motivation), which expands the literature on the internal mechanisms between negative emotions and pro-environmental behavior, and extends scholars' understanding of the serial mediating processes between cognition and motivation in air pollution environment. Finally, this paper adds to the research on the moderating effects of people’s regulatory focus on their daily coping strategies in the context of air pollution, which is helpful to further explore the dynamic effects of emotions on behaviors.