Heat shock proteins (HSPs) are known to protect cells from oxidative stress and other types of injuries. We previously reported the neuroprotective effect of HSP70 following cerebral ischemia and reperfusion using hsp 70.1 knockout (KO) mice. However, the precise role of HSP70 in neuroprotection has not been established yet. The purpose of this study was to investigate the relationship between HSP70 and antioxidant enzymes using hsp 70.1 KO mice. The activities of both SOD-1 and SOD-2 were significantly decreased in hsp 70.1 KO mice than in the wild type (WT) littermates. SOD-1 protein level in the hsp 70.1 KO mice was lower than that of WT. We speculate that HSP70 might be involved in regulation of expression of SOD-1 at the level of transcription or by post-transcriptional modification.