Designing high-performance microwave absorption materials become a prominent demand with the rapid development of information technology. In this work, needle-like morphology of aluminum nitride (AlN) decorated multi-walled carbon nanotubes (MWCNTs) as microwave absorbers has been successfully fabricated through a facile oil bath treatment. The MWCNTs/AlN composites exhibit outstanding microwave absorption performance with different content of MWCNTs, and the mass ratio of MWCNTs/AlN to paraffin is 2:3. The minimum reflection loss can reach to - 47.34 dB at 9.12 GHz when the absorber thickness is 2.9 mm and the effective absorption bandwidth is 3.28 GHz with the composites containing 7 wt% MWCNTs. More importantly, the lowest density of MWCNTs/AlN composites can reach 0.316 +/- 0.0294 g/cm(3), which is beneficial for practical applications. The significant improvement in microwave absorption properties of MWCNTs/AlN is major attributed to the enhancement of impedance matching, dielectric loss and multiple scattering by introducing different content of MWCNTs. This work might build an ideal to design novel lightweight, high-performance and broaden applications of microwave absorption materials, which can be widely used in practical fields under special conditions. [GRAPHICS] .