Teacher enthusiasm is receiving remarkable scholarly attention in L2 education, and its effect on students' language learning outcomes has been extensively investigated. Nevertheless, exploring the antecedents of language teacher enthusiasm has received scant attention in foreign language education, particularly within the Chinese context. Thus, informed by the principles of positive psychology, the present study investigated the extent to which English as a foreign (EFL) teachers' enthusiasm can be predicted by their work engagement and foreign language teaching enjoyment (FLTE) in the context of China. The study involved three online questionnaires completed by 576 EFL teachers in China. The results of structural equation modeling revealed that teacher work engagement and FLTE were strong predictors of Chinese EFL teachers' enthusiasm. In addition, EFL teachers' FLTE was a better predictor of their enthusiasm than their work engagement. The findings highlighted the importance of applying positive psychology in foreign language education. Finally, the paper concludes with avenues for future research.