This paper discussed Chengqi Decoction associated prescriptions and clinical application by Wu Jutong.Wu Jutong inherited Sanchengqi Decoction that proposed by Zhang Zhongjing and made it flourish in Detailed Analysis of Epidemic Warm Diseases(Wenbing Tiaobian),which expanded clinical application category and enriched the differentiation and treatment system of fever. By making careful and detailed analysis and comparison on the Chengqi Decoction associated prescriptions and the modified formula in Detailed Analysis of Epidemic Warm Diseases,this paper discussed the inheritance and change of Wu’s Chengqi Decoction for Zhang Zhongjing’s purgative method,and summarized the mechanism and common used prescriptions,which aimed to investigate the medication rule and clinical application of Chengqi Decoction associated prescriptions.