Abstract: In order to establish the rate model of simultaneous liquefaction and saccharification ( SILS) , simultaneous enzymatic hydrolysis of the micronized corn flour samples were carried out using commercially available a- amylase and glucoamylase, and effect of p H and temperature on rate constant and glucose yield were studied.Experimental results showed that the kinetics of SILS accorded with the character of the two order reaction. Both the glucose yield and reaction rate constant were affected significantly by the p H of feed mixture ( p < 0.05) . The effect of SILS temperature on the glucose yield was not significant ( p > 0.05) , but it had significant effect on the reaction rate constant ( p < 0.05) . Under the condition of temperature at 60 ℃ and p H at 6.0, the highest glucose yield reached 84.6% and the reaction rate constant was 0.0088 ( g / L) - 1·h- 1.In the temperature range of 30⁷0 ℃, the relationship between reaction rate constant and temperature could be expressed by Arrhenius equation. The activation energy was 3.3 × 104J·mol- 1for the SILS of micronized corn flours. The study on the Kinetics and activation energy of SILS could provide a good guiding significance for application in production.