The reaction of quinoline-methyl iodide in salicylic aldehyde has been studied by conducto-metric method,The second order velocity constants of the reaction have been found as follows:4.37 × 10^-3 liter per mole per minute at 25°C,9.57 × 10^-3at 35°C,and 19.8 × 10^-3 at 45°C respectively.The value of the activation energy of the reaction has been determined to be 14,200 cal,per mole,and that of the entropy of activation,-32.0 cal.per mole lxr degree at 45°C.