Diagnostic elements 1, middle-aged and elderly onset, slowly progressive course. 2. At least two of the four main signs (resting tremor, myotonia, bradykinesia, abnormal posture and gait) are present, and at least one of the first two is present, and the symptoms are asymmetrical. (1) Resting tremor: It is often the first symptom, starting on one side, with a “pill-rolling” movement, which is obvious at rest. (2) Myotonicity: It can be manifested as “leadpipe like myotonicity or” or “gear like myotonicity”. (3) Motor retardation: reduced casual movements, slow and clumsy movements, may show “mask face”, “writing too small sign”. (4) Abnormal posture and gait: “panic gait” when walking. (3) Levodopa treatment is effective. (4) No extraocular muscle paralysis, cerebellar signs, upright hypotension, extrapyramidal damage and muscle atrophy.