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.