Adjuvants aimed at increasing the immunogenicity of recombinant antigens remain a focus in vaccine development. Worldwide, there is currently considerable care for the development of biodegradable microspheres as controlled release ofvaccines, since the major disadvantage of several currently available vaccines is the need for repeated administration.Microspheres prepared from the biodegradable and biocompatible polymers, the polylactide (PLA) or polylactide-coglycolide(PLGA), have been shown to be effective adjuvants for a number of antigens. This review mainly focuses onpolylactide-co-poly(ethylene glycol) (PELA) microspheres adjuvant as vaccine delivery systems by summarizing our andother research groups' investigation on properties of the microspheres formulation encapsulating several kinds of antigens.The results indicate that compared with the commonly used PLA and PLGA, PELA showed several potentials in vaccinedelivery systems, which may be due to the block copolymer have its capability to provide a biomaterial having a broad rangeof amphiphilic structure. PELA microspheres can control the rate of release of entrapped antigens and therefore, offerpotential for the development of single-dose vaccines. The PELA microspheres have shown great potential as a nextgeneration adjuvant to replace or complement existing aluminum salts for vaccine potential. The review mainly aims topromote the investigation of PELA microspheres adjuvant for antigens for worldwide researcher.