In order to improve high temperature oxidation resistance of niobium alloy, electroless plating combined with pack cementation technologies was used to obtain composite coatings with or without CeO2 particles. The microstructure and high temperature oxidation resistance of the composite coatings were investigated. Al/Ni coating contains NiAl phase, while Al/Ni-CeO2 coating is made up of NiAl, NiAl3, Al3Nb and CeO2, etc. The oxidation test of the composite coatings was carried out at 1000℃. The results show after 50 h oxidation mass gain of the Al/Ni composite coating was 8.0 mg/cm2, with the formation of Al2O3 and AlNbO4 phase; The mass gain of the Al/Ni-CeO2 composite coating after 50 h oxidation was 4.0 mg/cm2, with Al2O3, CeO2, NiAl, NiAl3, Al3Nb and AlNbO4 phase. On the surface of two coating systems continuous dense Al2O3 scales were detected with good adhesion to the coating. CeO2 particles were mainly aggregated in the interdiffusion zone under the drag force of Ni. The addition of CeO2 particles refines the coating structure, reduces the consumption of Al element in the coating, fills the holes, and enhances the adhesion of the scales to the coating, so as to improve the oxidation resistance of the coating.