Background: Previous studies have shown that young adults are faced with physical, emotional, and psychological threats due to the COVID-19. In particular, the overall level of physical activity (PA) among college students has markedly decreased during the pandemic. It is necessary to find underlying mechanisms of PA behavior in COVID-19, as health-related behaviors formed during the college years can be maintained throughout a lifetime. Purpose: The present study aimed to examine the impact of perceptions toward COVID-19 and PA on PA participation among South Korean university students. Methods: Data were collected online from 150 South Korean undergraduate students. Gender-stratified multiple regression analysis was used to identify the relationships between perceptions and PA. We also analyzed moderate PA (MPA) and vigorous PA (VPA) separately to identify different aspects of PA participation according to the type of PA in the COVID-19 context. Results: Regression analysis revealed that both male (Coef=432.64, p<.01) and female (Coef=396.21, p<.05) students were more participate in VPA if they had higher self-efficacy. By contrast, males more participated in MPA when they had fewer barriers to PA (Coef=–161.31, p<.05); females preferred MPA when they perceived the risk of COVID-19 infection to be low in their current health status (Coef=–76.44, p<.05). Conclusions: It would be effective to alleviate fear of risks of COVID-19 for female students, while removing physical barriers for male students, to break the negative behavioral patterns and promote PA participation.