目的 探讨新型冠状病毒肺炎中医证素分布、组合规律及疾病分期的证素演变规律。方法 通过检索公开发表的新型冠状病毒肺炎中医诊疗方案、论文等文献，建立数据库，采用频次频率、关联规则方法分析证素分布、证素组合规律，通过贝叶斯网络分析不同分期证素分布的条件概率。结果 共纳入相关文献42篇，212条记录。提取证候要素25个，其中病位证素12个，以肺、心神（脑）、脾为主；病性证素13个，以湿、热（火）、毒、气虚为主。证素组合分布以单一病性证素 + 病位证素、两病性证素 + 病位证素的组合形式为主；共得出寒、湿、肺，热（火）、气脱、心神（脑），气虚、肺、脾3组强关联组合。疾病初期病性证素以湿、寒、热（火）为主，病位主要在肺、卫分；进展期（中期）病性证素以毒、热（火）、湿、痰为主，病位主要在肺；危重期病性证素以毒、热（火）、气脱为主，病位主要在肺、心神（脑）；恢复期病性证素以气虚、阴虚为主，病位证素主要在肺、脾。结论 新型冠状病毒肺炎病因以湿邪为主；病位在肺，可累及脾，重症可及心神（脑），湿毒壅肺为主要病机，以“湿、毒、热、闭、虚”为主要证素特点。
Objective To explore the TCM syndromes elements distribution， combination rule and the evolution of syndrome elements in disease stages of Corona Virus Disease 2019 (COVID-19).Methods Through searching the diagnosis and treatment plans of COVID-19 and literatures about COVID-19, established database, analyzed the distribution of syndrome elements and the combination rule of syndrome elements by frequency and association rules mining, and analyzed the probability of distribution of syndrome elements in different stages by Bayesian network.Results 42 articles were included (212 records). 25 syndrome elements were extracted, 12 syndrome elements of disease location were included, in which lung, mind (brain) and spleen were the main disease location; 13 syndrome elements of disease characters were included, dampness, heat (fire), in which toxic and Qi deficiency were the main disease characters. The distribution of syndrome element combination was mainly in the form of single syndrome element of disease location + syndrome elements of disease characters, and two syndrome element of disease location + syndrome elements of disease characters. Three groups of strong association combinations were obtained: dampness, cold, lung; heat (fire), qi collapse, heart spirit (brain); Qi deficiency, lung, spleen. In the early stage of COVID-19, the pathogenic elements were mainly damp, cold and heat (fire), and the disease location was mainly in the lung and defense tier; in the advanced stage (middle stage), the pathogenic elements were mainly toxic, heat (fire), dampness and phlegm, and the disease location was mainly in the lung; in the critical stage, the pathogenic elements were mainly toxic, heat (fire) and qi collapse, and the disease location was mainly in the lung and mind (brain); in the recovery stage, the pathogenic elements were mainly qi deficiency and yin deficiency, and the disease location was mainly in the lung and spleen.Conclusion COVID-19 was mainly caused by dampness and the disease was located in the lung, which could involve the spleen, and critical stage could involve heart (brain). The core pathogenesis of COVID-19 was dampness-toxicity obstructing lung, and it could be characterized by "dampness, toxin, heat, closure and deficiency".