This study reports an empirical case study about using interdisciplinary approach in business English courses with 41 English majors in the Chinese university context. The methodologies are two-stage surveys, teacher reflection and participant observation. The results show that participants most preferred using specialist vocabulary and cross-cultural business communication as learning activities in using interdisciplinary approach. The challenges and difficulties in interdisciplinary learning included lack of professional vocabulary, business or interdisciplinary knowledge, business thinking skills and inadequate language skills. A majority of the participants perceived the interdisciplinary approach as effective, as they had improvements in business language, knowledge, communication and English ability. For improving and refining the interdisciplinary approach, participants suggested more practical and detailed business knowledge, practice-based activities, oral simulation and role-play activities, more detailed guidance and feedback in the writing tasks, more business cases with interesting videos, increasing Chinese native language explanation and producing a business English language corpus.