Children are not smaller-sized adults, their tissues, organs and functions change dramatically from newborn to adolescence. Pediatric drug development and clinical trials are important safeguards for children's drug safety. However, pharmaceutical research and clinical trials are difficult to perform in children, which is a universal problem in the world. This article reviews the policies, regulations, and clinical trials of pediatric drugs in Europe, America, and China, which intends to provide references for the future development of pediatric drug clinical trials in China.