OBJECTIVE: To assess the toxicity of moxa smoke in rats.METHODS: Forty-eight female Wister rats were randomly divided into 4 groups(n = 12/group) to simulate moxa smoke exposure in Chinese medicine clinics(CMCs): the control group, and three moxa-smoke exposed groups of PM10 mass concentrations 3-5, 7-9 and 27-30 mg/m~3, respectively.These concentrations were 1 ×, 2-3 ×, and 7-9 ×fold the concentrations found in CMCs. Exposures continued for 12 weeks(200 min/d, 5 d/week).RESULTS: No deaths were noted. After the exposure, the body weights, ratios of organ weight to body weight, urinary parameters, hematological parameters, clinical chemistry parameters and microscopic examinations revealed no obvious toxicity.CONCLUSION: Moxa smoke did not induce toxic effects in female rats in the study. These findings provide new evidence to the toxicity of moxa smoke.