Blood tests in patients with Parkinson’s disease are generally unremarkable, but secondary, hereditary Parkinson’s syndrome needs to be excluded as a differential diagnosis. In patients with hypertension, history of stroke, and basal ganglia lacunar infarction, blood tests such as blood glucose, lipids, blood uric acid, and serum homocysteine need to be completed to understand whether there is a risk of cerebral atherosclerosis, thus excluding vascular Parkinson’s syndrome. If serum copper blue protein, copper oxidase activity, and blood tests for serum copper levels are in the normal range, hereditary Parkinson’s syndrome due to hepatomegaly can be tentatively excluded. Patients with hepatic encephalopathy and hypothyroidism can also develop secondary Parkinson’s syndrome. Blood tests for liver function, blood ammonia and thyroid function can be drawn to rule out this type of disease. Patients who have been taking thiazide antipsychotics such as chlorpromazine and fenazepam for a long time, as well as those taking drugs such as reserpine and flunarizine, need to have their relevant blood levels monitored to rule out drug-related Parkinson’s syndrome. The diagnosis of Parkinson’s disease can be considered if the patient has a history of slow, progressive exacerbation, often with unilateral onset, with reduced movement as a necessary symptom, and at least one of the three symptoms of resting tremor, muscle rigidity, and postural gait instability, and is sensitive and effective to dopamine agents, in addition to excluding related non-Parkinsonian diseases.