Objective:To investigate the differential expression of proteins in the cerebrospinal fluid of patients with schizophrenia. Methods:A total of 12 patients with schizophrenia and 12 patients without schizophrenia were enrolled. Cerebrospinal fluid was collected,and two-dimensional polyacrylamide gel electrophoresis for protein separation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for protein recognition and identification were used to screen out symbolic proteins in cerebrospinal fluid. Results:There was a significant difference in the content of Clus-human protein between the schizophrenia group and the non-schizophrenia group(2.560 6±0.319 2 μg/L vs. 2.134 9±0.418 7 μg/L,t=2.801,P=0.010). Conclusion:Clus-human protein is found in the cerebrospinal fluid of patients with schizophrenia and may have important significance in the diagnosis of schizophrenia.