objective:to develop a sandwich elisa system for quantitative measurement of the human connective tissue growth factor(ctgf), and to detect the sera ctgf level of human. methods:after labeled the purified monoclonal antibodies(mabs) with horseradish peroxidase (hrp) by sodium oxidation method, the antibody-pair matching(for capturing and detection of antigen, respectively) was performed using anti-ctgf mab as coating antibody and hrp labeled anti-ctgf mab as labeled antibody,the optimal concentrations of anti-ctgf mabs were defined by titration. standard curve was performed using purified ctgf protein,the effectiveness of this sandwich elisa system was evaluated by sensitivity, reproducibility and recovery rate. the ctgf levels in sera of health people, hbsag(+) without hepatocellular carcinoma (hcc) patients and hbsag(+) with hcc patients were measured by this system. results:the optimal paired antibodies were anti-ctgf mab 3h5 and hrp labeled anti-ctgf mab 4c5 with optimal concentrations of 40 μg/ml and 1∶4 000 respectively. the sensitivity of this elisa system was 1.46 ng/ml. the average coefficients of variations were 4.59% within assay and 5.70% between assays. the recovery rate was (98.73±4.84)%. the ctgf levels in sera of 40 health people, 76 hbsag(+) without hcc patients and 35 hbsag(+) with hcc patients were [2.65(2.16±3.18) ng/ml], [5.53(2.74±8.23)ng/ml],[8.77(4.81±13.65) ng/ml],respectively. the difference among these groups showed great significance(p < 0.001). conclusion:a sandwich elisa system for quantitative measurement of human ctgf was successfully established. the serum level of ctgf in hbsag(+) with hcc patients raises significantly compare with hbsag(+) without hcc patients and normal group. this suggests that ctgf may be a potential biomarker for the forewarning of hbsag (+) with hcc.