PURPOSE: COVID-19 has had a huge impact on the physical behavior and mental health of people. Long-term and strict isolation policies are widely used to ensure social distancing, which may cause excessive smartphone use and increase the risk of smartphone addiction. Previous researchers have identified that some factors that affect smartphone addiction, but there was little research conducted during COVID-19 pandemic. The present study aims to examine the effect of peer phubbing on smartphone addiction, how boredom proneness may mediate this effect, and lastly how refusal self-efficacy may moderate the indirect and direct pathways during COVID-19 pandemic. METHODS: A total of 1396 college students (mean age=20.48, SD=1.08) were surveyed and completed four scales (Peer Phubbing Scale, Refusal Self-efficacy Scale, Smartphone Addiction Index Scale, Boredom Proneness Scale). The statistical analyses were conducted by SPSS 22.0 and SPSS PROCESS macro. RESULTS: This study found that peer phubbing was positively associated with smartphone addiction. Boredom proneness mediated the effect of peer phubbing and smartphone addiction. Furthermore, refusal self-efficacy moderated the relationship between peer phubbing and smartphone addiction as well as boredom proneness and smartphone addiction. Specifically, peer phubbing had a greater impact on smartphone addiction for college students with higher levels of refusal self-efficacy, and the boredom proneness on smartphone addiction was stronger for college students with low levels of refusal self-efficacy. CONCLUSION: This study is important in investigating how peer phubbing is related to the smartphone addiction of Chinese college students during COVID-19 pandemic. The results suggest that college students' boredom proneness and refusal self-efficacy may be prime targets for prevention and intervention programs. Thus, this study explored "how" and "when" peer phubbing may enhance college students' smartphone addiction during COVID-19 pandemic.