Although typical clinical features of Parkinson's disease are widely accepted, the symptoms of individual parkinsonian patient are variable. We reviewed here the possible classification of the disease in terms 1) degree of response to levodopa, 2) rates of progression, 3) age of onset, and 4) main symptoms. In order to select a most appropriate therapeutic drug, we proposed other points for classification, 5) development of wearing-off, 6) with or without severe dementia and 7) characteristic clinical features, i.e. akinetic form, frozen form and so on. For the evaluation of long-term effects of anti-parkinsonian drugs, it is important to classify the patients by the course of alteration of cardinal or characteristic symptoms.