The theory of the spleen and stomach is a summary of LI Dongyuan's long-term clinical practical experience，which has been continuously supplemented and developed by later physicians，thus forming a complete theory.The authors briefly analyzed the modern research of LI Dongyuan's theory of the spleen and stomach from three aspects，including theoretical discussion，medication rules and clinical application，and found that most of the past researchers didn't combine the theory with practical problems like constitution and living habits of modern people.Combining the concrete conditions of“internal damage of the spleen and stomach causing various kinds of diseases”，the authors believe that the etiology of most diseases is the constitution and living habits of modern people，and the pathogenesis is spleen-stomach deficiency cold.Therefore，during the treatment，attention should be paid to protecting the middle yang as well as regulating and soothing the spleen and stomach.The paper discusses the understanding of the modern application of theory of the spleen and stomach from three aspects of etiology，pathogenesis and treatment，in order to open our minds on clinical diagnosis and treatment of miscellaneous diseases.