Learning environment and student engagement (SE) are widely considered valuable to foreign language learning, but how they influence foreign language achievement (LA) remains underexplored. Drawing on sociocultural theory, this survey study explored the impact of the online learning environment (OLE) on LA of Chinese as a Foreign Language (CFL) and the mediating role of SE among 447 international students in China by using structural equation modeling. The results indicated that: (1) the participants had favorable perceptions toward OLE, SE and LA; (2) OLE factors, i.e., accessibility of online learning materials, student interaction, and course organization significantly positively influenced LA, whereas teacher support did not influence LA; (3) SE mediated the positive effects of all the OLE factors on LA. The results suggest that enhancing online learning environment and increasing student engagement are effective means to improve online CFL learning achievement.
Fan et al. (2026) studied this question.