Objective To examine the relationship between serum YKL-40 level and cerebral hemorrhage volume and nerve function damage, and to identify the risk factors that influence the prognosis of spontaneous intracerebral hemorrhage (SICH) patients.Methods Patients with cerebral hemorrhage in the basal ganglia region (100 cases) were assigned to the test group. Based on the degree of nerve injury, patients were further divided into the mild injury group (n=30), moderate injury group (n=46), and severe injury group (n=24). In addition, patients were also divided into mild (<10 ml) hemorrhage (n=35), moderate (10-30 ml) hemorrhage (n=46), and severe (>30 ml) hemorrhage (n=19) groups according to the volume of cerebral hemorrhage. Meanwhile, 50 healthy individuals who underwent physical examination during the same period of time were selected as the control group in this study. Serum YKL-40 levels were measured on days 1, 3, 7, and 14 post-admission, and the prognosis of patients was evaluated using the modified Rankin Scale at 3 months post-admission. Independent risk factors that affect prognosis were analyzed by multivariate logistic regression.Results Serum YKL-40 levels were significantly higher in the test group than in the control group (P<0.001). Serum YKL-40 levels in the mild, moderate, and severe hemorrhage groups were increased gradually in the first 7 days, reaching a peak on day 7, and then decreased gradually (P<0.05). In addition, serum YKL-40 levels were significantly higher in the severe injury group than in the mild and moderate injury groups (P<0.05). At 3 months post-admission, 54 patients showed good prognostic outcome, while 32 patients showed poor prognostic outcome. Multivariate logistic regression analysis showed that age, NIHSS at admission, intraventricular hemorrhage, and YKL-40 were independent risk factors that influence the prognosis of SICH patients.Conclusions Serum YKL-40 is correlated with the volume of cerebral hemorrhage and the degree of nerve function injury, and can be used as a reference for the clinical diagnosis and prognosis of SICH patients.