Biotransformation has strong selectivity，high catalytic efficiency，mild reaction conditions，various reaction types and less environmental pollution properties，and was increasingly applied in Chinese medicinal and natural drugs，which provides a new technolo or substitute for modern pharmaceutical raw materials.It is of great significance in exploring active ingredients，expanding resources and protecting resources of Chinese medicinal.Based on the latest research at home and abroad，the paper analyzes the significance of biotransformation technology for the development of Chinese medicinal，summarizes the biological system of transformation reaction，its main reaction types and the influencing factors of biological transformation，and provides ideas and methods for further research.