Peroxisome proliferator-activated receptor (PPAR) is a member of the nuclear receptor superfamily, which is activated by various hydrophobic compounds. PPAR has 3 subtypes (PPARalpha, gamma, and delta) showing different expression patterns. Each PPAR subtype has homologous domains (DNA binding domain and ligand binding domain). PPARalpha plays a role in the clearance of circulating or cellular lipids via the regulation of gene expression involved in lipid metabolism in liver and skeletal muscle. PPARgamma promotes adipocyte differentiation to enhance blood glucose uptake. PPARdelta is involved in lipid oxidation and cell proliferation. Therefore, all PPAR subtypes are indispensable for the regulation of wholebody lipid metabolism.