Perception of fear of missing out (FoMO) has been a prevalent phenomenon in social media users. Adopting questionnaire survey, the finding shows that Chinese social media users are experiencing FoMO, and younger people with higher level of FoMO. In detail, FoMO is significantly related to social media engagement, both of its frequency and single-use time. And sex is a important moderator, females are more likely to increase social media engagement, it was different from non-Asian users in dealing with FoMO. The finding also shows FoMO can promote users information behavior, such as liking, commenting and forwarding, but the promotion of information avoidance behavior, such as diving, shielding and ignoring, requires further research.