Abstract： Objective： To study the compatibility rules of prescriptions containing medicinal pair of Coptidis Rhizoma and Pinelliae Rhizoma using data mining technology．Methods：The prescriptions containing medicinal pair of Coptidis Rhizoma and Pinelliae Rhizoma were collected and sorted from the Encyclopedia of Chinese Medicinal Formulas and Collection of Traditional Chinese Medical Books．The frequency statistics were conducted using Microsoft Excel 2019． Based on the Apriori algorithm and using IBM SPSS Modeler 18.0 software， the main diseases treated， compatibility combinations， association rules， and nature， flavors and effects of medicinal pair of Coptidis Rhizoma and Pinelliae Rhizoma were explored and its medication rules in different diseases were studied．The association rule network diagram was drawn． Results： There were a total of 416 prescriptions containing the medicinal pair of Coptidis Rhizoma and Pinelliae Rhizoma，involving 339 single Chinese medicinals．Among them，those with higher compatibility frequencies with the medicinal pair were Glycyrrhizae Radix et Rhizoma （ 232 times），Poria（ 226 times）， Citri Reticulatae Pericarpium （215 times）， Scutellariae Radix （167 times）， and Atractylodis Macrocephalae Rhizoma （140 times），etc. There were 121 main diseases treated，including phlegm-fluid retention，stomach upset and abdominal mass． Based on association rule analysis， the core medicinal combinations were Coptidis Rhizoma- Pinelliae Rhizoma-Glycyrrhizae Radix et Rhizoma， Coptidis Rhizoma-Pinelliae Rhizoma-Poria， and Coptidis Rhizoma-Pinelliae Rhizoma-Citri Reticulatae Pericarpium， etc． Conclusion： The medicinal pair of Coptidis Rhizoma and Pinelliae Rhizoma is often combined with bitter-acrid Chinese medicinals for increased curative effect with the core compatibility mechanism of “regulating ascending-descending with acrid-bitter pairing”．In clinical practice， it mainly used for diseases of phlegm-fluid retention，stomach upset and abdominal mass and exerts its curative effect by regulating qi movement and dissipating phlegm-damp with heat accumulation.