To analyze the rule of Chinese medicine against chronic pyelonephritis based on the data mining method and provide references for clinical regimens.Methods:The prescriptions of Chinese medicine in the treatment of chronic pyelonephritis from literature in recent decades were collected and recorded into the software of the Traditional Chinese Medicine Inheritance Support System(V30).The mutual information method and complex system entropy clustering method were used to analyze the composition rules of the prescriptions against chronic pyelonephritis.Results:Ninety-six prescriptions against chronic pyelonephritis were screened out and analyzed.There were 4 compositions(Poria，Dioscoreae Rhizoma，Glycyrrhizae Radix et Rhizoma，and Rehmanniae Radix) with the frequency of use more than 20 times.In terms of the four properties of Chinese medicines，most Chinese medicines had cold properties.In terms of the five flavors of Chinese medicines，most Chinese medicines had sweet flavors.Most Chinese medicines were attributed to the lung meridian and kidney meridian，with the efficacy of tonifying deficiency.The correlation coefficient was found in 8 commonly-used medicine pairs with the support degree of 167%，and 4 core combinations were obtained.The red tongue was the most frequent in the tongue manifestation，and the thin pulse was the most frequent in the pulse manifestation.The syndrome of dampness-heat was the most common the syndrome statistics.Conclusion:The compatibility of high-frequency medicines reflects the principle of the treatment of chronic pyelonephritis with traditional Chinese medicine，which focuses on eliminating pathogens and reinforcing healthy qi，using the medicines with tonifying kidney and invigorating spleen，clearing heat and draining dampness，and replenishing qi and nourishing yin effects.