Abstract: The present invention relates to a normal-pressure hydrocephalus diagnosis composition and diagnosis marker detection method which use the level of expression of chitinase 3-like 1 (CHI3L1) in blood and, more specifically, to a normal-pressure hydrocephalus diagnosis composition and diagnosis kit which comprise a preparation for measuring the expression level of CHI3L1 protein or of mRNA encoding the protein, and to a normal-pressure hydrocephalus diagnosis method using same. According to the present invention, the expression level of CHI3L1 is significantly increased in patients with normal-pressure hydrocephalus. Thus, the present invention is excellent since it can rapidly and accurately diagnose normal-pressure hydrocephalus by analyzing the expression level of CHI3L1.