When commercial products could not fulfill the clinical needs of some special patients, it is necessary for pharmacists to take the practice of compounding. Pharmacy compounding is still an important activity in the modern health care system. However, pharmaceutical compounding is one of the highest risk activities among pharmacy practice. In the United States, pharmacy compounding of human drug products not only has to comply with the regulations in section 503A of the Federal Food, Drug, and Cosmetic Act, but also needs to follow the sterile preparations and non-sterile preparations guidelines in the U.S. Pharmacopeia (USP). By reviewing the regulations of pharmacy compounding in the U.S. code and the standing of pharmacy compounding advisory committee in the Code of Federal Register, along with coordinating the general chapters of pharmaceutical compounding in the USP, we strive to find out the spirit of these Acts and regulations, and aim to develop the regulations of pharmacy compounding in Taiwan.