Abstract: Methylal is synthesis form methanol and tormaldehyde in the liquid phase inpressence of strong acidic cation exchange resins catalyst.It is a reversible reaction. The intrinsic kinetics study was performed in a batch reactor.The effects of reaction temperatureand concentration of catalyst on the reaction rate were studied and the kinetics parameterswas estimated in terms of linear or nonlinear least square method.The kinetic model was obtained.The verification of the model showed that the model imitated the experimental well.