Objective: The Four Medical Tantras is a classic work of Tibetan medicine, in which drug treatment is one of the four main treatment methods, and prescriptions are the main form of clinical drug use. The study on the medication rules of The Four Medical Tantras has positive significance for the clinical medication research of Tibetan medicine. Method: Prescriptions recorded in Secret Medical Code and Follow-up Medical Code from The Four Medical Tantras were collected, the prescription database was constructed by Visual FoxPro 9.0, combined the dual perspectives of the " fifteen categories" (skabs bco lnga) of Tibetan medical diseases and the " eighteen practices" (lag len bco brgyad) of treatment, and Gephi 0.9.2 complex network was used to analyze its medication rules. Result: The Four Medical Tantras contained 2 695 Tibetan medicine prescriptions, average number of drugs in each prescription was 6.6, prescription composed of ≤ 7 drugs accounted for 69.2%of the total prescription. There were 1 002 kinds of medicines involved in the total prescription, of which 156 was the nodal degrees of Chebulae Fructus, Bambusae Concretio Silicea, Carthami Flos, Piperis Longi Fructus and Zingiberis Rhizoma and so on; followed by 91 nodal degrees of butter (mar), sugar, barley sweetener (sbang ma), honey and brown sugar and so on, which were Tibetan medicinal and edible medicines. According to the classification of diseases in the fifteen categories, there were 495 prescriptions for traumatology (mtshon rma), 323 for fever (tsha ba), 278 for toxics and 197 for three factors diseases. According to the treatment method of eighteen practices, 162 powder, 77 decoction, 84 laxative (bxhal) and others were used. Association rule analysis found that edge weights of Borneolum Syntheticum, Bambusae Concretio Silicea, Carthami Flos, Santali Albi Lignum and other cold medicines were 59, edge weights of pomegranate seeds, Piperis Longi Fructus, Cinnamomi Cortex, Amomi Fructus Rotundus and other warm medicines were 45. Conclusion: The Four Medical Tantras has some characteristics, including the medication rules of elliptic philosophy with cool-warm medicinal properties as the dual core, elimination-diarrhea (zhi-sbyong) as medication methods, weight of rlung-mkhris pa-bad kan as medication dialectical thinking and so on. Among them, the clinical application of butter, barley sweetener, sugar and other special delivery agents of Tibetan medicine is prominent. The prominent clinical application of special Tibetan medicines embodies the philosophy of Tibetan culture with the emphasis on overall balance. It has the multi-dimensional medication rule of " diet plus medicine, medicine plus therapy", and has positive significance for revealing the research on medication rules of Tibetan medicine.