A preparation method of glutaraldehyde by one step oxidation of cyclopentene with peroxyformic acid is reported. The preparation is carried out in a mild reaction condition, time saving and without catalyst. The product is identified by MS and IR measurements. The results showed that the highest yield of glutaraldehyde 56 7% is obtained at optimum molar ratio of n (hydrogen peroxide)∶ n (cyclopentene)∶ n (formic acid)=1∶3∶3, reaction temperature 35 ℃ and reaction time 1 h.
