To study the medication rule of traditional Chinese medicine(TCM) compounds in the treatment of chronic atrophic gastritis.Methods:The patent library of China National Intellectual Property Administration was searched to obtain the patent data of TCM compound for treating chronic atrophic gastritis.Then the data were imported into the Traditional Chinese Medicine Inheritance Support System(V2.5) for frequency statistics,association rule analysis,and complex network construction.Results:A total of 189 TCM patent compounds were included.The high-frequency Chinese medicinal materials were Rhizoma Atractylodis Macrocephalae and Radix Glycyrrhizae.The medicinal materials were mainly warm,cold,moderate in property,and bitter,sweet,pungent in flavor,and mainly acted on spleen,stomach,and liver.The most common drug pair and triple drug combination were Rhizoma Atractylodis Macrocephalae-Poria and Rhizoma Corydalis-Rhizoma Atractylodis Macrocephalae-Radix Paeoniae Alba,respectively.The association rule with high confidence was Radix Glycyrrhizae,Poria→Rhizoma Atractylodis Macrocephalae,and the new obtained prescription via entropy-based hierarchical clustering was Cortex Magnoliae Officinalis-Fructus Aurantii Immaturus-Endothelium Corneum Gigeriae Galli-Herba Artemisiae Scopariae.Conclusion:The basic pathogenesis of chronic atrophic gastritis was deficiency of spleen and stomach,with deficiency-excess in complexity as the pathological characteristics and blood stasis as the important disease trend.The treatment should be based on invigorating spleen and replenishing qi and focus on activating blood and resolving stasis.