Abstract:α-Benzildioxime(α-1) and β-benzildioxime(β-1) were prepared by nucleophilic addition reaction of benzil(2) and hydroxylamine hydrochloride(3). The structures were confirmed by 1H NMR and IR. Under optimum conditions[2 10 mmol, n(2) : n(3)=1:5, methylbenzene as solvent, triethylamine as acid binding agent, dropping time of 3 was 4 h and pH=8, at 55 ℃ for 5.5 h], the yield of β-1 was 90.4%.