Abstract：The only existing copy of Yuanyou Xinfa is a pediatric monograph written by Peng Yongguang in Ming Dynasty， which contains a total of 3 volumes. In this book，the authors discussed necessary precautions on pregnancy- delivery and children care- nursing， described the etiology and pathogenesis of pediatric diseases， four examinations and medication， therapeutic principles and treatment methods， and prescription- determining according to syndrome. The book plays an important role in clinical syndrome differentiation and treatment of pediatric diseases.