RESUMEN
OBJECTIVE: To analyze the mechanism of clinical hold in USA and to provide reference and enlightenment for clinical trial review process reform in China. METHODS: Analyzed the regulation, review process, reasons and impacts of drug clinical hold in USA and compared with clinical trial system in China, then provided advice for our country. RESULTS AND CONCLUSION: FDA review IND by implied license process within only 30 d, and may permit the clinical trials begin as early as possible, the clinical trial could be imposed on hold, and the hold could also be lifted or transfer into inactive status, thus protect the health and rights of subjects to the largest extent, and in the same time improved the review efficiency. It is necessary and feasible that clinical hold is introduced into clinical trial system in our country.