Parkinson disease (PD) is characterized by the degeneration of dopaminergic neurons in the substantial nigra and the formation of intracellular Lewy body. Protein nitration due to oxidative and nitrative stress has been linked to the pathogenesis of PD. Here we described the biophysical and biochemical properties of α-synuclein and nitrated α-synuclein protein and reviewed their biological consequences; finally we discussed their roles in the mechanism and prevention/treatment of PD.