In this paper, the superplastic deformation behaviour of a pulse electrodeposited Ni-SiC nanocomposite was further studied at temperatures ranging from 330 to 530oC. It was found that optimum temperature of the composite was 450oC, and the shape of its flow stress vs strain rate curves is similar to that of conventional superplastic materials. The microstructures of the composite before and after deformation were examined using SEM and TEM. Dislocations and deformation twinning were observed in the deformed samples, and there was significant grain growth during deformation. The deformation mechanisms were also discussed in the paper based on the experimental findings.