To study the time-related changes of the infrared thermal images (ITI) of human body and their correlation with meteorological factors. Methods:Three double-blind randomized trials were carried out with placebo or drug control, in winter, spring and summer respectively. Three researched TCM health foods were Shengsheng Capsule (immunity adjustment), Shengan Capsule (sleep improvement) and Shengyi Capsule (decreasing serum lipid). Images were scanned every 6 days during 36-day trial period, with scanning time variation <2h. We explored the correlation between ITI features (indicator of health care effects) and time, and meteorological factors (e.g. temperature, humidity, air pressure, cold front passage and tropical cyclone landing). Results:Each image features demonstrated a respective tendency of time-related variations. However, the trial group and placebo group shared the same variation tendency for each feature, and some long-term effects of health food were reflected in certain time spots within the first 36 days. Some special ITI changes are closely related to meteorological and other factors, which needs further studying. Conclusions:ITI is a sensitive display technology of human body, and by displaying the body's function change under the impact of TCM health foods and meteorological factors, it will have significant application in health monitoring.