Peptide∶N-glycanase (PNGase) is a deglycosylation enzyme widely presented in fungi, plants, mammals and other eukaryotics. Only two bacterial PNGase have being isolated (PNGase F and PNGase F-II) thusfar, and both are used widely as research tools in glycomics. PNGase catalyzed the hydrolysis of the amide bond between N-acetylglucosamine and an Asn residue on an N-glycoprotein, generating a de-N-glycosylated protein and a complete N-oligosaccharide. After the reaction, the N-glycosylated Asn residue was converted to Asp. Although it is known that PNGase participates in protein degradation, organ development, individual growth and other key biological processes in organisms, its impacts on health was illustrated only recently. Human PNGase (NGLY1) deficiency could lead to a genetic disease named congenital disorder of deglycosylation-NGLY1. A nematode PNGase deficiency could reduce its life span. Its defects in mice could be embryonic lethal. This article describes the distribution, protein structure, and biological function of PNGase in different species. It can serve as an important information resource to support basic research for PNGase mechanism and innovative study for PNGase applications.