In metal matrix composites (MMCs), the reinforcement/matrix interface has a profound effect on its overall properties. The proper selection or design of the interfacial phase plays a vital role in optimizing the final properties of MMCs, in which high damping capacity is one of the most important properties of materials used in engineering structure. Although the damping mechanism of discontinuously reinforced aluminum composites has been extensively studied, only a few of researches have been reported on the effect of whisker coatings on the damping capacity of MMCs. In this paper, the pure aluminum matrix composites reinforced by alumina borate (Al₁₈B₄O₃₃) whisker with and without Bi₂O₃ coatings were separately fabricated by squeeze and the volume fraction of Al₁₈B₄O₃₃ whisker in these composites is about 20%. The mass ratios between Al₁₈B₄O₃₃ whisker and Bi₂O₃ were set as 6∶1, 10∶1 and 20∶1, respectively. The effects of coating contents and strain amplitudes on the damping properties of the coated composites at various temperatures and frequencies were examined. Two damping peaks (P1 and P2) in the coated composites at around 80 and 285 ℃ were observed. The results of damping characterization indicate that the damping capacity of the coated composites strongly depends on the content of coatings and strain amplitudes. Moreover, P2 increases more rapidly with increasing the coating content and strain amplitude. P1 is related to dislocation motion and interfacial slip between the whisker and Bi phase. The damping mechanism of P2 changes with the increase of stain amplitude.