Abstract： Objective： With the help of Traditional Chinese Medicine Inheritance Support System(TCMISS) V2.5， this paper analyzes the prescription and administration rules in the treatment of hematemesis in Linzheng Zhinan Yi'an written by YE Tianshi. Methods： The prescriptions for hematemesis in Chapter 2 Hematemesis， volume 2 of Linzheng Zhinan Yi'an were input into the TCMISS V2.5. The rules of prescription and administration in the treatment of hematemesis by YE Tianshi were analyzed via complex system entropy clustering technique， modified mutual information method， unsupervised entropy hierarchical clustering and other data mining methods. Results： According to the statistical analysis of 213 prescriptions for hematemesis，the top five Chinese medicines with higher frequency were Sclerotium Poriae Pararadicis， Poria，Radix et Rhizoma Ginseng，Radix Rehmanniae Recens，and Radix Ophiopogonis. Besides，26 core combinations and 13 new prescriptions were obtained. Conclusion： The rules of YE Tianshi's prescriptions for hematemesis inherited the treatment concept of ZAHGN Zhongjing： first， use Chinese medicines with sweet and warm nature to invigorate middle yang，care for the stomach qi，and fortify the spleen and replenish qi；second，emolliate the liver and nourish yin，and regulate wood and soothe the liver；third，regulate the defense qi，and use light Chinese medicine to nourish.