In this study, a recombinant DJ-1 protein was administrated into the brain of PD model rats that had been injected to 6-hydroxydopamine (6-OHDA) in the left substantia nigra. PD phenotypes, including dopaminergic neuron death in the substantia nigra, decrease in dopamine, and dopamine transporter levels in the striatum, and motor abnormality, were dramatically improved by wild-type DJ-1 but not L166P DJ-1, a mutant form of DJ-1 found in PD patients.;Importantly, DJ-1 expression decreases markers of oxidative stress after stroke insult in Vivo, suggesting that DJ-1 protects through alleviation of oxidative stress.