Mill’s five canons is a kind of inductive logic

including method of agreement

method of difference

combination method of agreement and difference

method of concomitant variation and method of residues. Medication principles in Treatise on Cold Pathogenic and Miscellaneous Diseases were analyzed by the above five methods respectively. The authors found that the symptom of "Qi uprush"corresponded to Guizhi Decoction application by deducing with the method of agreement. The symptom of "Qi uprush"corresponded to Guizhi [Ramulus Cinnamomi

桂枝]application by deducing with the method of concomitant variation and combination method of agreement and difference. The symptom of "rigid neck and back"corresponded to Gegen [Radix Puerariae

葛根] application by deducing with the method of difference and method of residues. Results showed that Mill’s five canons could be looked as a tool or a method to help analyze the relationship of different phenomenon. It could be adopted to explore the principles of Zhang Zhongjing using prescriptions

herbs and syndromes

as well as causality.