The incidence of each of the rare disease is very low. The complexity and diagnosis difficulty of the rare disease lead to the difficulties in the clinical research and development (R&D) of drugs for rare diseases. There is an urgent clinical need for the drug development of rare diseases in China. Encouraging R&D of new drugs, particularly the innovative drugs with China's own independent intellectural property is the basis for solving the predicament in drug shortage in China.. In order to further improve the efficiency of clinical R&D of drugs for rare diseases, the National Medical Products Administration (NMPA), Center for Drug Evaluation (CDE) issued Technical Guidance for Clinical Research and Development of Drugs for Rare Diseases. This is the first guidance for rare diseases in China that is drafted from the standpoint of the clinical technology research and development.The guidance is the scientifitc thinking and framework for the drug developing enterprises to research and develop drugs for rare disease efficiently and appropriately by following drug developing protocols and relating to the special features of rare disease.This paper presents the concepts and rationale in the guidance for the appraisal of rare disease drug research and development.