In recent years, the willingness to communicate among L2 learners (L2WTC) across different cultural and educational contexts have attracted increasing attention from the academic community. A variety of emotional, psychological and situational factors have been scrutinized for their direct and indirect effects on WTC. However, the personal factor of grit in shaping WTC has been insufficiently investigated, and the possible mediating effects of L2 emotions (e.g. foreign language enjoyment and anxiety) have been relatively under-explored. Based on a sample of 301 Chinese undergraduate English majors, this study investigated the influence of the two dimensions of grit, i.e., perseverance of effort (PE) and consistency of interest (CI), on two types of L2 WTC, i.e., meaning-focused and form-focused L2 WTC; and explored the possible mediating effects of foreign language anxiety (FLA) and three sources of foreign language enjoyment (FLE-private, FLE-atmosphere, and FLE-teacher) in their relationship. It is found that: (1) PE significantly positively predicted meaning-focused and form-focused L2 WTC; (2) FLE-private and FLE-atmosphere fully mediated the relationship between PE and meaning-focused and form-focused L2 WTC, and that (3) FLE-atmosphere fully mediated the relationship between CI and meaning-focused and form-focused L2 WTC.