Research on self-efficacy has been a productive field and abundant research has shown that teachers’ self-efficacy beliefs influence teachers’ actions and performances and thus affect students’ learning outcomes. However, there is a lack of literature on EFL teachers’ self-efficacy beliefs and even less research was set in Chinese EFL contexts. On the one hand, this study was conducted to provide a general picture of the current status of EFL teachers’ perceived English proficiency, self-rated self-efficacy beliefs and self-reported teaching practices in terms of some demographic perspectives; On the other hand, it aimed to explore the correlations among Chinese primary EFL teachers’ perceived English proficiency, self-efficacy beliefs and teaching practices. The quantitative study surveyed 217 in-service primary EFL teachers. The descriptive results showed that: (1) EFL teachers varied in perceived English proficiency in terms of age, years of teaching experience and college major; (2) age and teaching experience did while college major didn’t make a difference for EFL teachers’ self-efficacy beliefs; (3) the surveyed EFL teachers, in general, had a greater preference to communication-oriented language teaching (COLT) than form-oriented language teaching (FOLT). The results from the correlational statistics showed that: (1) perceived English proficiency (PEP), on the whole, had a significant predictive effect on self-efficacy beliefs (SEB). It was striking that among the four skills (listening, speaking, reading, and writing) of English language, speaking had the most significant predictive effect on self-efficacy beliefs; (2) EFL teachers’ self-efficacy beliefs (SEB) had a predictive effect on COLT practices whereas not on FOLT practices; (3) The mediation model of showing the causal impacts of PEP (through SEB) on COLT was tested. i.e. Chinese primary EFL teachers’ self-efficacy beliefs played a complete mediating role between perceived English proficiency and communication-oriented language teaching. The findings of the present study added on the compelling evidence that self-efficacy beliefs matter in the realm of primary EFL teaching in China. In light of these findings, implications were generated to primary EFL teacher education and in-service EFL teacher training programs, such as courses related to improving English proficiency, especially speaking skills, should be offered for non-English major EFL teachers; training courses related to improving self-efficacy beliefs, especially on classroom management strategies, and the recommended communicative-oriented language teaching practices should be offered to pre-service and inexperienced in-service EFL teachers.