Objective To explore the relationship between the characteristics of five circuits and six qi(shorten as Wuyun Liuqi)in the birth year of the patients with common tumors and the occurrence of common tumors,and to evaluate the potential value of the Wuyun Liuqi theory in modern epidemiological research of tumors.Methods Clinical information was collected from the SEER(Surveillance,Epidemiology,and End Results)database(1975-2020)and from the Department of Oncology,Huizhou Hospital of Guangzhou University of Chinese Medicine in the recent 3 years.The birth year of the patients with common tumors were converted into the Wuyun Liuqi elements of zhongyun(yearly circuit),guest qi,dominant qi and combination of circuit and qi.The correlation of the Wuyun Liuqi elements with the risk of various types of tumors was explored by LASSO regression analysis,monofactorial regression analysis and multivariate logistic regression analysis.Results(1)A total of 2 215 896 cases were enrolled in the study,of which 2 215 024 cases were from SEER database,1 158 019 being male(52.28%)and 1 057 005 being female(47.72%).The rest of 872 cases were from our hospital,including 527 males(60.44%)and 345 females(39.56%).Breast cancer,prostate cancer,lung cancer,colorectal cancer,gastric cancer and liver cancer were involved.(2)It was found that there was a significant correlation between some Wuyun Liuqi elements and the occurrence of specific types of tumors.For example,the occurrence of lung cancer was related to insufficient tuyun(earth-element in motion)while the occurrence of breast cancer was related to the year of insufficient shuiyun(water-element in motion),indicating that there may be a potential relationship between the Wuyun Liuqi elements at birth with the risk of tumors.Conclusion The preliminary findings of this study support the feasibility of applying the theory of Wuyun Liuqi in predicting the risk of various types of tumors.However,for the complicated relationship between the characteristics of Wuyun Liuqi and tumorigenesis,further research is needed to explore the mechanism behind it.To provide more evidence for the establishment of risk prediction models and the practical application of traditional Chinese medicine concept of preventive treatment of disease in tumor prevention and treatment,future research should cover a larger population sample and more detailed birth time,and take family history,geographical factors and environmental factors.