_{:Dense niobium coating was successfully prepared by atmospheric pressure chemical vapor deposition(CVD) method at 1150℃ ,which reached 250μm / h deposition rate. Analysis the post-deposition coating thickness by the gas flow direction,the mole percentage of NbF5, H2, HF and Arin different positionsweredetermined. And got agrowthkinetics equation which agrees well with the experimental results . Further analysis of the kinetic equations showed that the byproduct HF has a greater impact on deposition rate and Ar almost no effect.}