OBJECTIVE: To identify individual-level and organisation-level enablers and barriers to the provision and consumption of healthier foods at worksite canteens in China and to develop a theoretical framework and evidence-based, specific, practical intervention strategies. DESIGN: Mixed-methods formative research, with in-depth interviews, focus group discussions and quantitative questionnaires. SETTING: Two community health centres (CHCs) in Pudong, Shanghai, China. PARTICIPANTS: In-depth interviews with three CHC administrators and three canteen managers and staff. Six focus groups with a total of 19 male and 36 female employees, aged 25-67 years. RESULTS: Three subthemes were identified as important for influencing individual food choice: the cultural perception of 'eating well', the need to balance taste preferences and nutrition, and the emphasis on food safety in healthfulness. At the organisation level, two related subthemes emerged: the balance of canteen budget and food safety with the variety and quality of offerings, and the interplay between key stakeholders. Key barriers included cost, poor communication between employees and management, individuals' emphasis on taste over healthfulness, variation in individual preferences and discordance between perceived and actual weight status, particularly among men. Key enablers included strong, positive food culture in China and trust in canteen food. An ecological framework to describe determinants of worksite food environment in Shanghai was developed and intervention strategies were mapped onto this framework. CONCLUSIONS: A balancing act occurs at multiple levels and ultimately determines the worksite food environment and employee food choice at CHCs in Shanghai of China. There is a need to implement these findings and evaluate their impact on diet and health.