Abstract: Chemical vapor deposition (CVD) is one of the most efficient methods to synthesize carbon nanotubes (CNTs). This paper presents a model to simulate synthesizing CNTs by using a nozzle-type CVD reactor model. The model comprises of the conservation equations of mass, momentum, heat, the mass fractions of the reactant, product species and chemical reaction. Based on the model, this paper simulated the product distribution and the rate of carbon deposition velocity distribution in the nozzle-type CVD reactor or the CVD reactor without a nozzle, and compared the variation of carbon deposition rate of nozzle-type CVD reaction at different temperatures. The simulation results show that the nozzle type CVD reactor is more efficient than the CVD reactor without a nozzle. Moreover, at a certain temperature range,the carbon deposition rate increases as the temperature rise.