Abstract: Objective To investigate the distribution characteristics of Chinese syndromes and syndrome elements in COVID-19. Methods The modern traditional Chinese medicine (TCM) literature about COVID-19 in China knowledge network (CNKI), Wanfang database, Weipu database and Medline database from January to April 2020 was retrieved. Referring to TCM Diagnostics, TCM Syndrome Differential Diagnostics, TCM Clinical Diagnosis and Treatment Terminology-S Syndrome Part, TCM Digital Syndrome Differentiation Machine developed by Zhu Wenfeng in 1 978 and related research results of “973 Project”. The resolution method of syndromes and syndromes elements was used to standardize and split the types of nonstandard and compound syndromes, and to extract the syndrome elements of disease location and disease type. The statistical analysis was performed with descriptive statistical method (frequency/rate). Results Ten TCM syndromes literature were included to study. Compared with the latest version of the diagnostic criteria (7th edition), only 56.14% of the syndromes types reported in these literatures was involved in the nine syndromes types proposed in the criteria. A total of 58 types of syndromes were reported in the literature (with a total frequency 1 587). After standardization, 43 types of syndromes were referred to with a total frequency 1 732. The common syndrome types with frequency over 5% were Yidu-Bifei, Shire-Yufei, Hanshi-Yufei, Feipi-Qixu, Shixie-Yufei, and Qiyin-Liangxu. The cumulative frequency of these six syndromes was 989, accounting for 57.10% of the total syndromes. For 15 kinds of syndrome elements of disease location after literature standardization, the frequency of occurrence was 1 777 times, with Fei, Pi, Wei, Weifen, Qifen, and Shen(Xin,Nao) as the common syndrome elements of disease location (frequency>2%), accounting for 95.94% of the total disease location syndrome elements. A total of 20 types of syndrome elements which appeared 2 567 times with occurrence frequency >2% were Shi(Waixie), Bi(Fei, Xinshen, Naoqiao), Qixu, Du(Yi, Re, Han), Shire, Yu, Re(Waixie, Feng), Shi(Neisheng), and Yinxu, accounting for 81.65% of the total disease type syndrome elements. Conclusions The complexity of the etiology and pathogenesis of COVID-19 led to the diversity of syndrome differentiation system. Whatever the syndrome type is, we should pay attention to the importance of “Feipi-Qixu” in the development of disease.

Key words: COVID-19, syndromes, syndrome elements, distribution characteristics, literature research