To explore the medication rules of State medical master Yan Zhenghua.Methods:The prescriptions including Radix Paeoniae Rubra that built by Pro.Yan were collected to build a database based on Traditional Chinese Medicine (TCM) inheritance assist system.After analyzing the statistical reports module and the data analysis module which were from TCM inheritance assist system,the methods of data-mining including association rules and apriori algorithm were used to analyze the frequency of single medicine,the frequency of drug combination,the association rules between drugs and core drug combinations of prescriptions that all included Radix Paeoniae Rubra.Results:The prescriptions including Radix Paeoniae Rubra were commonly used to treat megrim,stomach-ache,arthralgia-synadrome and other syndromes.The highest frequency used drugs were Cortex Moutan,Radix Paeoniae Alba,Pericarpium Citri Reticulatae.The most frequency drug combinations were “Radix Salviae Miltiorrhizae,Radix Paeoniae Rubra”,“Radix Paeoniae Alba,Radix Paeoniae Rubra”,“Radix Paeoniae Rubra,Pericarpium Citri Reticulatae”.The drug association rules whose confidence level was 1 were “Radix Glycyrrhizae->Radix Paeoniae Rubra”,“Cortex Moutan->Radix Paeoniae Rubra”,“Chaff Flower Root->Radix Paeoniae Rubra”,and “Radix Paeoniae Alba->Radix Paeoniae Rubra”.Conclusion:The drugs in the prescriptions containing Radix Paeoniae Rubra that built by Pro.Yan mostly have the effects of regulating the flow of qi and invigorate blood circulation,which reflects the clearly thoughts when making prescriptions.