OBJECTIVE： To analyze the formulation regularity of Chinese patent medicines containing Paeonia lactiflora， and to provide evidence for modern clinical application and R&D of P. lactiflora. METHODS： The formulations of Chinese patent medicine containing P. lactiflora were collected from Chinese Materia Medica Preparation and 2015 edition of Chinese Pharmacopeia. Statistical analysis was performed on the frequency of medicinal material， channel tropism， distribution of attending syndromes and attending diseases， core medicine combination （support degrees were set as 10％， 20％， 30％ and confidence degree was 0.9） by using data mining methods such as descriptive statistics and association rule analysis in TCM Inheritance System V 2.5； the formulation regularity of common attending syndromes and attending diseases （support degrees were set as 20％， 30％， 40％ and confidence degree was 0.9） was analyzed. RESULTS： A total of 600 Chinese patent medicine formulations contained P. lactiflora， involving 673 ingredients. The main medicinal properties in Chinese patent medicines containing P. lactiflora were warm， followed by cold and neutral. The main medicinal flavor was sweet， followed by bitter and pungent. The main channel tropism was spleen， liver and heart channel. There were 165 kinds of main treatment diseases （menstrual disorder， dysmenorrhea， dizziness） and 159 main treatment syndromes （insufficiency of qi and blood， qi stagnation and blood stasis， liver and kidney deficiency）. Under the condition of 30％ support degree and 0.9 confidence degree， there were 20 core combination of Chinese patent medicine formulations containing P. lactiflora （Glycyrrhiza uralensis-P. lactiflora， Angelica sinensis-P. lactiflora， P. lactiflora-Poria cocos） and 19 association rules among drugs. Under the condition of 40％ support degree and 0.9 confidence degree， there were 8 core medicines in Chinese patent medicines containing P. lactiflora for menstrual disorders （such as P. lactiflora， Cyperus rotundus， A. sinensis）， 9 core medicines for dizziness （such as P. lactiflora， Rehmannia glutinosa， A. sinensis）， 9 core medicines for qi and blood deficiency （such as P. lactiflora， Atractylodes macrocephala， P. cocos）， and 10 core medicines for qi stagnation and blood stasis syndrome （such as P. lactiflora， Aucklandia lappa， G. uralensis）. CONCLUSIONS： In this study， data mining was used to analysis the main symptoms， compatibility characteristics and formulation rules of Chinese patent medicines containing P. lactiflora， which can provide a basis for the modern clinical application and new drug development of P. lactiflora.