We investigated the impact of work–family conflict on job insecurity according to conservation of resources theory, and examined the mediating role of core self-evaluation in this relationship. In addition, we investigated if men and women show differences in their levels of work–family conflict. Participants were 378 employees of a stateowned enterprise in China, and we analyzed the data using correlation analysis and the bootstrapping method. Results show that work–family conflict was positively correlated with job insecurity and negatively correlated with core self-evaluation, with men experiencing greater work–family conflict than women did. Further, core self-evaluation was negatively correlated with job insecurity, and also mediated the relationship between work–family conflict and job insecurity. We have used conservation of resources theory to broaden understanding of job insecurity. Suggestions are provided for ways managers can alleviate employees' job insecurity.