Purpose: The purpose of this paper is to investigate the use of mobile assisted language learning (MALL) in vocabulary learning among English foreign language learners in China with a lens on academic major difference. This study hypothesizes that academic majors including Science, Technology, Engineering and Mathematics (STEM) and non-STEM differentiate the learners' perception of computer self-efficacy (CSE) and MALL learning performance as well as moderate the effect of CSE on language learning performance. Design/methodology/approach: Sample data for this study were collected from 200 university students enrolled in both STEM and non-STEM majors. Under the quasi-experiment, this study had been conducted vocabulary training, pre-test, post-test and a questionnaire. The Statistical Package for the Social Sciences, a statistical analysis technique based on ANOVA and regression were used to analyze the data. Findings: The results support hypotheses that CSE, learning score and satisfaction are rated higher for STEM students than non-STEM ones and indicate the effect of CSE on language learning performance is stronger for STEM students than non-STEM ones in using MALL. Originality/value: This paper addressed important issues in language learning on the academic major difference. The findings would be the guidelines for educational organizations to motivate and stimulate students with sustainable self-confidence important not only for improvement in students' language learning achievements and outcomes but also for the advancement of mobile technology in language learning.