Recently, the Center for Drug Evaluation (CDE) of the State Food and Drug Administration issued a notice on the "Technical Guidelines for Pharmaceutical Changes in Marketed Biological Products (Trial)". The guidelines will be implemented from the date of issuance (June 25, 2021). Contains 9 chapters including overview, basic principles, basic requirements, change of production process, change of excipients in formulations, change of specifications or packaging specifications, change of registration standards, change of packaging materials and containers, change of validity period or storage conditions. The guiding principles apply to preventive biological products, therapeutic biological products, and in vitro diagnostic reagents managed by biological products, and explain the basic ideas and concerns of the research on changes in the registration and management of biological products after the market.