Objective To analyze and discuss the medication rule of professor Ruan Yan in the treatment of children with allergic rhinitis by using data mining method,and to provide reference for the clinical research and patented drugs development for the treatment of children with allergic rhinitis.Methods The outpatient medical records of professor Ruan Yan for the treatment of children with allergic rhinitis were collected.Microsoft Excel 2010 software was used for frequency statistics.SPSS Clementine 12.0 software was used for association rule analysis,cluster analysis and factor analysis to obtain the data.The frequency of use of various drugs and the association rules between drugs were obtained.Then the medication rules in professor Ruan Yan's prescription were analyzed.Results A total of 308 Chinese medicine compounds were included,involving 80 kinds of Chinese medicines,among which relieving drugs and qi-invigorating herbs were high-frequently used.The distribution of traditional Chinese medicine syndrome types was mainly characterized by lung-qi deficiency-cold syndrome and lung-spleen qi deficiency syndrome.The medicinal properties were mainly spicy,warm and sweet,and most of them belonged to the lung,spleen and stomach meridians.Five core prescriptions were extracted by factor analysis.Four drug combinations were obtained by systematic cluster analysis.Conclusion Ventilating lung and opening the orifices,expelling wind and removing cold,strengthening the spleen and replenishing qi are basic therapeutic principles for professor Ruan Yan in the treatment of children with allergic rhinitis.The treatment mainly focused on dispelling evil,ventilating lung and opening the orifices,expelling wind and removing cold during the acute stage of allergic rhinitis.In the remission period,according to the principle of"treating disease must be based on its origin",the treatment should enhance children's physical fitness,tonify lung and strengthen spleen,thereby reducing recurrence.