Multiple genetic and environmental factors are thought to cause idiopathic Parkinson's disease (PD). To identify the genetic factors, we are carrying case-control association studies by genome-wide MS (microsatellite) markers and SNP (single nucleotide polymorphism) markers on the candidate genes, and sib-pair analysis. We investigated 27,000 MS markers and found 8% of them were significantly associated with PD in the first screening. In the candidate gene approach, of 267 SNPs on 122 candidate genes, 22 SNPs on 16 genes showed significant p-values (less than 0.05) by chi-square statistics. The further analysis is necessary to identify causative genes for PD.