Abstract: Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily of transcription factors respond to specific ligands. PPARs molecule binds to the specific ligands, then binds to peroxisome proliferator response elements (PPRE) on DNA, regulating the expression of the target gene. Since PPARs was first cloned in rats, they had been cloned in human, rodents, amphibian, and fish. PPARs played a crucial role in glucose and lipid metabolism, cell differentiation, apoptosis, and inflammation. Thus, PPARs had been applied to the study of diseases. This paper briefly reviewed the structure, classification, and mechanism of PPARs. The main biological functions including lipid metabolism, glucose metabolism, and inflammation were summed up. Furthermore, the clone and expression of PPARα and PPARγ in mammal, fish and embryonic development were extraordinarily discussed. A brief review on the problem and the research trend of PPARs was also discussed in this paper.