A kind of kind of benzoic acid derivatives influenza neuraminidase inhibitors I to IV were prepared from the starting materials of 4-amino-3-iodine benzoic acid through a series of reactions , the compounds V - VII derivatived from compound II , and the structures were characterized by 1H NMR,13C NMR and MS.Inhibition rate determined by chemical fluorescence, and the activity test was performed by the influenza virus strains H3N2 (California / 04), H1N1 (California / 99) and B (Shanghai / 02), the results showed: Among the compounds I - IV, the greater side chain at C3 position,the lower activity of compounds; Among the compounds V - VII, introduction of hydroxyl on the α carbon in the side chains of benzene ring, the inhibitory activity stronger than single hydroxyl on β carbon, which suggested that the change of electronic environment on the α carbon had a greater influence on activity; Compound VIIcontaining single hydroxyl at α carbon in side chains of benzene ring possessed the strongest activity of type A influenza virus.