The rates of hydrolysis of N-(benzenesulfonyl) benzimidoyl chlorides (p-H, $p-CH_3,;p-CH_3,;p-NO_2;and m-NO_2$) have been measured by UV spectrometry in 60% methanol-water at $25^{circ}C$ and a rate equation which can be applied over wide pH range was obtained. Below pH 7.00, the substituent effect on the hydrolysis rate of N-(benzenesulfonyl) benzimidoyl chloride was found to conform to the Hammett ${sigma}$ constant with ${ ho}$ = -0.91, whereas above pH 9.00, with ${ ho}$ = 0.94. On the basis of the rate equation obtained and the effect of solvent, substituents and salt, the following reaction mechanism were proposed; below pH 7.00, the hydrolysis of N-(benzenesulfonyl) benzimidoyl chloride proceeds by $S_N1$ mechanism, however, above pH 9.00, the hydrolysis is initiated by the attack of the hydroxide ion and in the range of pH 7.00-9.00, these two reactions occur competitively.