Objective: To summarize and elucidate the characteristics and evolvement of Chinese medicine (CM) patterns reflecting the physical and mental conditions of participants in the Mars 500 long-term closed environment.Methods: The DS01-T Digital TCM Four-Diagnostic Instrument and CM Inquiring Diagnostic Questionnaire were used to collect information from 6 participants in the Mars 500 International Joint Research Project,through diagnostic methods of observation,palpation and inquiry according to CM theory.During the 520 days of the experiment,data collection was performed 37 times;a total of over 400 digital images of tongues and facial complexion and over 20,000 data were collected.These data were then analyzed by a team of experts in CM,statistics,and data mining.Results: The CM pattern evolvement of participants in the long-term closed environment followed some common trends.Qi deficiency was the main CM pattern observed,with individual features depending on constitutional differences[manifested in varying degrees of accompanying patterns of Gan (Liver) qi stagnation,Pi (Spleen) deficiency,dampness encumbering,or yin deficiency].Conclusion: The research has verified the effectiveness of CM syndrome differentiation based on the four diagnostic methods,which should serve as a solid foundation for observation,monitoring,and intervention in regard to the health conditions of astronauts in long-term space flights in the future.