<p>Unconditional self-acceptance (USA) is important for mental health. Studies reported that university students would develop the USA when they feel socially supported, included, and matter.  Nevertheless, those factors are dependent on social feedbacks. Amidst the COVID-19 outbreak is, they had to follow the social distancing protocols and interact online with each other. This change might have altered the way they perceive the social support and mattering. It is hypothesized that these alterations predicted their USA through their perceived social support (PSS) and the sense of social inclusion (state self-esteem). To test the hypothesis, 214 young adults (85 men, 129 women), aged between 18 to 25 (M=22.80, SD=1.92) were asked to complete a demographic form and the scales of each variable. Students from University X, Malaysia were chosen as the population as they studied fully online when we started this study; unfortunately, the university went back to physical study before we managed to collect our target sample size. The results of Bootstrapping with 5,000 samples and 95% confidence interval showed that state self-esteem (SSE) fully mediated the relationship between mattering and USA, while PSS did not. Therefore, the hypothesis of serial mediation was not supported.</p>