Disclosed is a use of phthalide compound for the preparation of a medicament. The medicament is especially used for treating and/or delaying the degeneration of Purkinje cells, and the phthalide compound is selected from the following group: butylidene phthalide, a metabolic precursor of butylidene phthalide, a pharmaceutically acceptable salt of the metabolic precursor of butylidene phthalide, a pharmaceutically acceptable ester of the metabolic precursor of butylidene phthalide, and any combination of the foregoing.