Two grafting starch was obtained by grafting copolymerization of two synthetical vinyl monomers using HRP/H2O2 as catalyst. The structure of vinyl monomers was verified by 1H-NMR.The grafting polymer was proof by structures were verified by FTIR. The effect of mass ratio of starch and vinyl monomer on the grafting efficiency (GE) and grafting percentage (GP) was studied. The highest GE and GP of the first grafting starch was 35% and 32%, 59% and 50% for the second grafting starch when the vinyl monomer ratio was 9%. The molecular mass tested by GPC for the two kinds grafting starch with highest GE and GP were 54 600 and 63 970. The two mostly grafted starches were used as retanning agent. The increase ratios in thickness were 18.1% and 18.6% respectively and the tanned leather has excellent softness and flexibility.