To investigate the medication rules of TCM in treating lung cancer.Methods:The TCM prescriptions for treating lung cancer were retrieved from The Complete Collection of Tumor Prescriptions，The Dictionary of Tumor Prescriptions，The Ministry of Health Drug Standard of Chinese Medicine Formulation，and The Promulgation of National Drug Standard(Revision).The data were entered into Excel for data processing，and Lantern 5.0，SPSS Modeler 18.0，and SPSS Statistics 25.0 were used for the frequency statistics，hierarchical cluster analysis，and association rule analysis of the prescriptions.Results:A total of 650 prescriptions were collected，involving 572 Chinese medicines which had the total frequency of 6 120.The Chinese medicines used in the prescriptions mainly had cold，warm，and plain natures，bitter，sweet，and pungent flavors，and tropism to the stomach，spleen，kidney，liver，and lung meridians.The most frequently used Chinese medicines were Astragali Radix，Hedyotidis Herba，Glycyrrhizae Radix et Rhizoma，Poria，Adenophorae Radix，and Ophiopogonis Radix.The high-frequency Chinese medicines mainly had the effects of clearing heat and removing toxin，replenishing qi and nourishing yin，and activating blood and resolving stasis.The association rule analysis yielded 16 pair associations and 24 triple associations of Chinese medicines，and 13 common factors were obtained within factors.The hierarchical cluster analysis yielded 7 closely associated medicine combinations.The latent structure analysis yielded 14 latent variables，each with 2 latent classes，totaling 28 latent classes.Conclusion:The TCM treatment of lung cancer，which is based on the principles of tonifying qi and nourishing yin，clearing heat and removing cancer toxin，activating blood and resolving stasis，invigorating the spleen and draining dampness，and clearing heat and resolving phlegm，remains to be validated by clinical and experimental studies.