The silicon-oxidation-kinetics of Deal-Grove has been improved. A novel physics model propounds a conception of reaction layer lying between oxide and silicon when the oxidation is going. The reaction is not only at the surface of silicon, as the model of Deal-Grove, but in the whole reaction layer. After the oxidation stopped the reaction layer will become a transition layer. An accurate analytic model of oxidation has been developed. It made of items, linear, parabola and logarithm. Of which, the factors are a, b, c and characteristic width d. In general, ad = c. In the area of 1-3000 nm, the new model fits very well with the experimental data. The paper explains the reactive rate of oxidation is of extreme lager in the beginning. Using the new model can get the width of transition area, The paper offers some model parameter tables and offers the relationship curves between the parameters and oxidation temperature. (C) 2003 Elsevier Ltd. All rights reserved.