Abstract: The reaction kinetics model of metal with nonmetal in molten aluminum is estblished on basis of the theories of kinetics and diffusion.The reaction mechanism of titanium and carbon in the Al-Ti-C system is that the TiC particles are formed through the reaction of titanium with carbon by titanium atoms towards the carbon particles and the TiC particles are dispersed by the convection of the molten aluminum. The effect of many factors, such as temperature of the molten aluminum,TiC volume fraction on the reaction rate of titanium and carbon is discussed,providing a theotical fundamentals for optimization of technological parameters.