New iodosobenzoic acid(IBA) such as 5-[N-(n-hexadecyl)-N,N-dimethyl-N-(β-ethyloxy) ammonium]-2-IBA was synthesized and its catalytic effects on hydrolysis reactions of p-nitrophenyldiphenylphosphate(PNPDPP), sarin(GB) and soman(GD) were determined. 5-[N-(n-hexadecyl)-N,N-dimethyl-N-(β-ethyloxy)ammonium]-2-IBA effectively catalyzed hydrolytic cleavage of PNPDPP. In kinetic studies of hydrolysis reaction using 5-[N-(n-hexadecyl)-N,N-dimethyl-N-(β-ethyloxy)ammonium]-2-IBA as a catalyst, it was shown that PNPDPP was cleaved with kφ(max)≥0.7965 sec(-1) which is 12~45 times more reactive than iodosobenzoate (kφ(max)=0.0645 sec(-1)) or iodoxybenzoate (kφ(max)=0.0178 sec(-1)) in aqueous cetyltrimethylammoium chloride(CTACl) micellar solution at 25±0.2 ℃ and pH 8.0. 5-[N-(n-hexadecyl)-N,N-dimethyl-N-(β-ethyloxy)ammonium]-2-IBA also catalyzed hydrolytic cleavage of GB and GD. The catalyst showed enhanced reactivity by 5.6(GD)~7.8(GB) times compared to 5-hydroxy-2-IBA in aqueous CTACl micellar solution at 25±0.2 ℃ and pH 8.0