ObjectiveTo observe the clinical efficacy and safety of treating mediate-risk pure ground glass pulmonary nodules （pGGNs） based on the state theory. MethodsA prospective clinical randomized controlled trial was used. Totally 141 cases of mediate-risk pGGNs were divided into treatment group （92 cases） and control group （49 cases） according to the random table method. The treatment group was given the basic Sanjie Formula （基础散结方） orally with modification according to the identification of traditional Chinese medicine （TCM） state， 1 dose per day， 3 months as a course of treatment.Three months after the treatment patients were checked by CT. Patients who were clinically judged as cure， moderate to low risk， and turned to surgical resection do not carry out a second course of treatment，and the rest of the patients continued to complete the second courses. Patients in the control group did not receive any treatment and were only followed up periodically. Patients in both groups received a CT review 3 months and 6 months after enrolled. Comprehensive curative effect was evaluated according to the reduction rate of the area of pulmonary nodules shown in chest CT， to further explore the clinical effective difference for patients at different TCM state； the risk of malignancy index （Mayo score） was calculated by Mayo model at enrollment and 3 months and 6 months after enrolled. Adverse events were monitored continuously during the study. ResultsDuring the follow-up， 8 cases in the treatment group and 7 cases in the control group were lost. A total of 126 cases completed the whole process， including 84 cases in the treatment group and 42 cases in the control group. The total effective rates at 3 months and 6 months of the treatment group were 46.15% （30/65） and 45.71% （32/70） in the treatment group， while the total effective rates at 3 months and 6 months in the control group were 12.5% （4/32） and 10.00% （4/40）. Compared with the control group， the comprehensive curative effect of 3 months and 6 months of enrollment in treatment group was significantly better than that in corresponding control group （P＜0.01）. The pulmonary nodule area and Mayo score in the treatment group decreased after 3 and 6 months of enrollment （P＜0.01）. In contrast， there was no statistically significant difference in nodule area between pre- and post-enrollment time points in the control group （P＞0.05）， and probability of Mayo risk increased in the control group after 6 months of enrollment compared to pre-enrollment （P＜0.05）. Among the 84 patients in the treatment group， there were 15 cases of qi deficiency state， 7 cases of yin deficiency state， 5 cases of yang deficiency state， 20 cases of qi depression state， 32 cases of damp-heat state， and 5 cases of harmonious state； the difference in the distribution of the total clinical effective rate of the patients with different TCM states after treatment was statistically significant （P＜0.05）， and the total effective rate of two-by-two comparison of qi depression state was higher （13/20，65.00%） than that of the total effective rate of damp-heat state （8/32，25.00%， P＜0.00833）. There were no significant changes in blood routine， urine routine， liver function and kidney function in both groups， and no adverse events occurred. ConclusionTreating mediate-risk pGGNs based on the state theory can effectively reduce the area of pulmonary nodules and inhibit the growth of malignant risk of pulmonary nodules.