The Sm3 doped Co2Z-type hexagonal ferrite materials were prepared by the conventional ceramic method and the microstructures and microwave absorbing properties of the materials were investigated. The influence of a certain amount of Sm3 addition on structures and microwave absorbing properties of the materials were investigated. The results show that Co2Z-type hexaferrite is still main phase in the Co2Z ferrite materials doped with Sm3 . It is observed that Sm-rich phase with granular morphology is dispersed in the main phase. The Sm3 doped Co2Z ferrite exhibited better microwave absorbing properties than the Sm3 undoped one. The maximum reflection loss of Sm3 doped Co2Z ferrite reached -20dB at 6.3GHz，and the frequency bandwidth of reflection loss more than 10 dB was 5GHz. The wave absorbing coating had good mechanical property and the adhesions of the coatings were higher than 10MPa.