Academic visitor programs aim to enhance university teachers' teaching and research capacity and intercultural competence. Its impact, however, has remained under-researched. Using the data collected from two rounds of in-depth interviews with 13 Chinese university English teachers over a year and a half, this study explored their experiences as academic visitors in the UK through the lens of professional identity. Findings revealed that the participants came with various expectations and negotiated and constructed different identities during their academic visits. The participants' developing identities in turn affected their investment in their professional development in their situated contexts. The study provides important implications for academic visit programs which need to be designed in line with the complex needs and identities of university teachers.