ObjectiveTo study the characteristics of imprinting template of flavonoid clusters in four Chinese medicines attributed to the lung meridian， and to establish an in vitro experimental approach for the study of the attribution of Chinese medicines to the lung meridian. MethodBased on 13 Chinese medicines， including Xanthii Fructus， Houttuyniae Herba， Fagopyri Dibotryis Rhizoma， Belamcandae Rhizoma and so on， which only belong to the lung meridian in Chinese Materia Medica（the 13^th Five-Year planning textbook of general higher education）， we identified four representative Chinese medicines， namely Houttuyniae Herba， Fagopyri Dibotryis Rhizoma， Belamcandae Rhizoma and Mori Cortex， and set up their fingerprints by high performance liquid chromatography（HPLC） and calculated the molecular connectivity indices of various components in the four Chinese medicines， the similarity to their mean value was calculated by included angle cosine method， so as to establish the quantitative relationship of construction versus imprinting ability， and to determine the order of each component in the lung meridian. A total of 7 reference substances， including chlorogenic acid， rutin， quercetin， isoquercitrin， hyperoside， epicatechin， and iridin， were selected to validate the overall conformational relationships of flavonoids of the model， as well as its predictive ability. ResultHouttuyniae Herba， Fagopyri Dibotryis Rhizoma， Belamcandae Rhizoma and Mori Cortex contained a total of 437 chemical components with an average molecular connectivity index similarity of 0.995 6. The four Chinese medicines contained a total of 204 flavonoids with an average molecular connectivity index similarity of 0.978 0， which was second only to the alkaloids with 0.985 1. The retention time（t_R） of the 7 reference substances showed a good conformational relationship with the similarity of the molecular connectivity index（t_R=831.4×S-790.3， r=0.861 4， P<0.01）， which was applicable to the in vitro attribution study of the position， similarity， and relative similarity with t_R of the cluster of 98.04% of flavonoids. Accordingly， the 1^st position was kuwanon D， with a similarity of molecular connectivity index of 0.987 7 and a t_R of 30.88 min， the 200^th position was chlorogenic acid， with a similarity of molecular connectivity index of 0.958 2 and a t_R of 6.36 min. The total first-order moment of the four Chinese medicines calculated by total statistical moment method of fingerprint was 24.26 min， ranked 21， which could characterize 99.19% of the whole， and the total first-order moment of the total peak area of the 7 reference substances in the four Chinese medicines was 20.00 min， with a rank of 46， which could characterize 98.68% of the whole. ConclusionFlavonoid clusters are suitable probes for the characterization of imprinting template for the study of the lung meridian， which can be established a quantitative imprinting method for meridian tropism of Chinese medicines in vitro.