Objective:To develop a simple,effective,low-cost,time saving chemiluminescent protein microarray to detect the serum CA19-9 level of patients with primary hepatic carcinoma.Methods:A protein microarray was developed for detecting CA19-9 levels in the serum samples after spotting mouse-derived CA19-9 monoclonal antibody on an aldehyde-based chip.Serum from primary hepatic carcinoma (n=46) and healthy controls (n=32) were tested by using this assay.Results:The results showed that 24 out of 46 patients with primary hepatic carcinoma had serum CA19-9 levels above 37 U/mL,and 22 out of 46 patients with primary hepatic carcinoma had serum CA19-9 levels under 37 U/mL.In healthy control,30 out of 32 total cases were under 37 U/ml.Only two healthy controls were 37 U/mL.The sensitivity,specificity and AUC of protein microarray were 52.17％,93.75％,0.688 [95％ CI:0.566,0.811].Conclusion:A chemiluminescent protein microarray method was established for detection of CA 19-9 in serum.