Objective To analyze the distribution of traditional Chinese medicine patterns in metabolic syndrome(MS),with the aim of deriving the attributes and characteristics of patterns in patients with MS more accurately and finely.Methods The data of 695 MS patients admitted to Dongfang Hospital,Beijing University of Chinese Medicine from December 2017 to September 2022 were retrospectively analyzed to derive traditional Chinese medicine patterns using latent class analysis and latent structure analysis,and the above results were used to identify the pattern type of each patient according to differentiation of syndromes,to determine the traditional Chinese medicine pattern types of MS patients.Results A total of 9,044 times of the symptoms and signs were included in this study,and the top 10 high-frequency symptoms and signs were dry mouth and polydipsia(77.70%),fatigue(60.58%),greasy fur(59.14%),blurred vision(54.68%),slippery pulse(53.96%),wiry pulse(52.09%),white fur(48.92%),numbness of the limbs(43.60%),yellow fur(39.71%),and cold limbs(36.40%).Based on the result of the latent class analysis,this study determined the main pattern elements of 695 patients with MS.The pathological pattern elements included qi deficiency,phlegm-dampness,dampness-heat,qi stagnation,yin deficiency,fire-heat,and impairment of body fluids;the pathological pattern elements were mainly located in liver,spleen,lung,and kidney;the 695 patients could be classified into three main groups:predominantly deficiency syndrome,predominantly excess syndrome,and deficiency syndrome accompanied with excess syndrome.Through analyzing the latent structure model of the symptoms and signs of 695 patients with MS,six basic syndromes were established,which were the syndromes of hyperactivity of liver yang,deficiency in the spleen with dampness retention,deficiency of both kidney yin and yang,consumption of body fluids due to intense heat,blood stasis due to qi deficiency,and stagnation of liver qi with stomach heat.Combined with the theory of Chinese medicine,the four-diagnosis information of 695 cases of MS was comprehensively integrated,and on the basis of latent class analysis and latent structure analysis,secondary syndrome differentiation of patients was performed.A total of 20 syndromes with a frequency of occurrence of>1%were finally obtained,with the highest frequency being the syndrome of stagnation of liver qi and spleen deficiency,internal retention of dampness-heat(12.66%).Conclusion The pathogenesis of MS is complex and the pattern types are widely distributed,but in general,the syndrome of stagnation of liver qi and spleen deficiency,and internal retention of dampness-heat is the most common.Therefore,clinically,based on syndrome differentiation and treatment,attention should be paid to combining the application of invigorating the spleen and soothing the liver,and clearing heat to resolve turbidity.