Abstract: Autoimmune diseases (AID) are characterized by autoimmune disorder, as autologous tissue is attacked by the autoimmune system. It is reported that the imbalance of autoimmune tolerance and ingrained inflammatory response are the core events of AID undoubtedly. Peroxisome proliferator-activated receptor γ (PPARγ) which belongs to the nuclear hormone receptor superfamily is a ligand activated transcription factor. PPARγ combines with retinoid X receptor (RXR) to form heterodimer. When PPARγ is activated, the complex regulates gene expression by binding to a specific peroxisome proliferator response element (PPRE). In addition, PPARγ has diversified biological functions, playing important roles in regulating metabolism, controling inflammation, modulating glucose and lipid metabolism, ameliorating atherosclerosis, anti-tumor, and regulating immune response. However, recently researches indicate that PPARγ participates in the pathogenesis of AID. PPARγ plays key roles in regulating activation and polarization of macrophages, function of dendritic cells, proliferation and differentiation of T cells, and modulation of the function of related stromal cells. This article summarizes the biological functions and signal transduction pathways of PPARγ and the protective effects of agonists of PPARγ on AID, aiming to provide theoretical support for the research of mechanism and prevention and treatment of AID.