To explore the mutual predictive relationship between mobile social media Fear of Missing Out (FoMO) and Mobile Phone Addiction (MPA) among vocational college students, to provide scientific reference for the prevention and education of college students’ mobile phone addiction behavior.

With the use of cluster random sampling, 1 000 college students from a vocational college in Shenzhen were investigated by mobile social media FoMO scale and MPA scale in September 2021 (T1) and December 2021 (T2). The data were analyzed by cross-lag regression analysis.

There was a significant positive correlation including the synchronous correlation and the consecutive correlation between mobile social media FoMO and MPA (P<0.05). Mobile social media FoMO T1 positively predicted MPA T2 (β=0.25, P<0.001), whereas MPA T1 did not predict mobile social media FoMO T2 (β=-0.01, P=0.76). Three dimensions of mobile social media FoMO could predict MPA synchronously (P<0.05) and behavioral performance T1 could predict MPA T2 consecutively (P<0.05). Two dimensions of MPA,loss of control and avoidance, could predict mobile social media FoMO synchronously (P<0.05), and avoidance T1 could predict mobile social media FoMO T2 consecutively (P<0.05).

Vocational college students with higher FoMO are more likely to have MPA. There is a one-way predictive relationship between mobile social media FoMO and MPA.