Abstract: Thirteen benzimidazolone derivatives were synthesized from isopropenyl-benzimidazolone via N-acylation reaction,and o-phenylenediamine and acetoacetic ester were used as starting material.The structures of the new derivatives were confirmed by 1H NMR,13C NMR and ESI-MS spectral analysis.Antimicrobial activity test indicated that compounds Ⅳ-01～Ⅳ-03 and Ⅳ-11,as well as the de-isopropenyl product of Ⅳ-02, Ⅳ-02a, have good inhibitory activity against the tested microbial.The MIC values of compound Ⅳ-02 were 0.78,12.5,1.56 and 1.56 μg/mL against Bacillus cereus,Bacillus subtilis,Staphylococcus aureus and Escherichia coil,and the EC50 value was 7.02 μg/mL against Botrytis cinerea,respectively.The de-isopropenyl product, Ⅳ-02a, showed the similarly antimicrobial activity as that of Ⅳ-02.