Abstract: γ-PGA-Mn conjugate,a novel free radical scavenger was prepared in the experiment through poly-γ-glutamic acid(γ-PGA),a carrier,chelation with Manganese ions.In the research γ-PGA,produced by microbial fermentation,was mixed with MnSO4 in the different mole ratios between COO-and Mn2+.The molecular composition and structure of the product γ-PGA-Mn conjugate were measured by ICPand IR,respectively.γ-PGA-Mn conjugate was also used to analyse its activities of slow-release and SOD through dialysis and xanthine oxidation,respectively.The resulting γ-PGAhad an molecular weight about 15ku after acid hydrolysis and then heating at 121℃ 0.1MPa for 20min.When the mole ratio of COO- and Mn2+ was 1:2,the combinated rate of γ-PGA-Mn conjugate was 91%.The γ-PGA-Mn cojugate had obvious ability to clean free radical and its SOD-like activity was 2513.78U/mL.The results suggest that γ-PGA-Mn conjugate has the activities of slow-release and anti-oxidation.