Fifty-five patients with Parkinson's disease were evaluated clinically and with brain CT in order to determinethe incidence of frontal cortical and subcortical atrophy. Twenty cases of age-related healthy control group werealso scanned. The CT criterias of frontal cortical atrophy that was used in this study were the maximum width offrontal hemispheric cortical sulci and width of anterior interhemispheric fissure between frontal lobes comparingwith maximum width of hemispheric cortical sulci except frontal lobes. And the criterias of frontal subcorticalatrophy were bifrontal index bicaudate index, and Evans index. The results are as follows: 1. Cortical atrophicchanges in Parkinson's disease were more prominent in frontal lobe rather than other causes of cortical atrophy.2. Frontal cortical and subcortical atrophic changes were also more prominent in Parkinson's disease rather thanage-related control group. 3. Subcortical atrophic changes in frontal lobe were always associated with corticalatrophic changes. 4. Changes of basal ganglia were hardly seen in Parkinson's disease. 5. Cortical atrophicchanges in frontal lobe must be the one of significant findings in Parkinson's disease.