The invention discloses application of an EPB41L4B gene in diagnosis and treatment of a Parkinson disease. It is proved by experiments that compared with a normal person, expression of the EPB41L4B gene in the blood of a Parkinson disease patient is up-regulated, and it is shown that whether a subject suffers from the Parkinson disease or not can be diagnosed according to the expression level of EPB41L4B in the blood. According to the research results of the application of the EPB41L4B gene in the diagnosis and treatment of the Parkinson disease, the EPB41L4B can further be used for preparing a drug for treating the Parkinson disease. According to the application of the EPB41L4B gene in the diagnosis and treatment of the Parkinson disease, the sensibility and the specificity of Parkinson disease diagnosis are greatly improved, and meanwhile a new target is provided for gene treatment of the Parkinson disease.