Objective To test the association between mitochondrial DNA(mtDNA) point mutations and praecox Parkinson's disease (PPD),and to investigate the characteristics of mtDNA mutations in Chinese patients with PPD. Methods Screening mtDNA A4336C, G5460A,A10398G,A13780G point mutations in 40 patients with PPD and 48 in control group was carried out by using Polymerase Chain Reaction (PCR), dot blotting, radiant developing. And sequencing was given to the nucleotide position (np)10256～np10577mtDNA of 20 patients with PPD and 20 subjects in control group.Results Out of the 40 patients with PPD, 20 (50%)had A10398G mutation. 6 (15%) had G5460A, 5(12.5%) had A13780G, 2 (5%)had A4336C, 19 (47.5%)had C10400T mutation. Out of the 48 controls, 7(14.6%) had A10398G, 24.2% had G5460A, 1 (2.1%)had A13780G and 20 (41.7%)had C10400T, but no any A4336C mutation was found in the controls. Thus, the ratios of A10398G,G5460A,A4336C,A13780G in patients with PPD were separately higher than those in the control group. Moreover significant difference was found in A10398G point mutation (P