Abstract: It is made that the model of Chemical Vapor Deposition Reactors with system of TiN deposition in a vertical cold-wall reactoi.The model including the fluid flow,heat and inass transfer can well used in strong free convcction fluid.The problcm is solved numer-ically by finite element method,using a velocity-pressure formulation for the momentum eq-uations.The dependence of density,viscosity,thermal conductivity and diffusion coefficienton temperature is considered.The distributions of velocity,temperture.TiCl_4 concentration in the reactor and the deposition rate of TiN on the substrat surface are prel1icted. The computa-tional results are in good agreement with experimental data.