Background:With the increasing concern of Healthy China and the development of information technology, mobile health enables patients access health information and interacting with doctors anytime and anywhere. Since the success of mobile health would depend on the adoption of patients, examining patients' willingness to use it is considered critical. Objective:This study aims to explore the determinants of mobile health services adoption among Chinese patients by an extended TAM with trust and perceived risk. Method:We conducted a questionnaire-based survey in three large Chinese hospitals, and analyzed the data with structural equation model. Results:The results reveal that the proposed model fits well. Specifically, trust, perceived usefulness and perceived ease of use positively correlate with mobile health services adoption. While, privacy risk and performance risk negatively correlate with the patients' trust and adoption intention toward mobile health. In addition, age and chronic condition of patients could predict their trust level and adoption intention towards mobile health respectively. Conclusion:We conclude that TAM works for the context of mobile health adoption in general, though the significance has declined. Supplementary to technical factors, trust and perceived risk are critical in explaining mobile health services adoption among Chinese patients.