There has been lots of progress in Parkinson's disease. First of all, in Japan, a guideline for the treatment of Parkinson's disease was published. This guideline contains both EBM based systematic review of every drugs being used in the treatment of Parkinson's disease including those drugs for the management of side effects and other problems arising during the course of the treatment and an algorithm of the practical treatment of Parkinson's disease patients. This is an official publication of Japanese Neurological Society. In the diagnosis of Parkinson's disease, many specialists in Parkinson's disease have recognized the usefulness of MIBG SPECT of the cardiac sympathetic endings. MIBG uptake shows remarkable decrease in Lewy body positive Parkinson's disease patients from the early stage except for some of the stage I patients. In the basic aspect, studies on familial forms of Parkinson's disease have contributed a lot to the understanding of the pathogenesis of sporadic Parkinson's disease. Mutations of alpha-synuclein cause autosomal dominant Parkinson's disease. Recently, triplication of one of the alpha-synuclein genes was found as the third mutation of PARK1. Thus just overproduction of normal alpha-synuclein is toxic to nigral neurons. In this form and sporadic Parkinson's disease, oxidative damage plays an important role in nigral neurodegeneration. PARK2 is caused by mutations of the parkin gene. Parkin protein is an ubiquitin-protein ligase. In this form also, oxidative damage appears to be operating in neurodegeneration. Thus a common mechanism appears to be present in different forms of Parkinson's disease. Future investigation to find neuroprotective drugs should take this concept of common mechanism into their research strategies.