Abstract: The chemiluminescence immunoassay kit (CLIA) for Prolactin(PRL) in human serum was developed.Two monoclonal antibodies against PRL were applied. One of the antibodies was coated on the microtiter plate,the other was labeled with HRP. The sensitivity of the assay was 4.26 mIU/L and the recovery was 90.3% -100.8%. The intra - and intera -ssay CV were less than 10% and 15% respectively. The results of dilution test demonstrated good correlation between dilution times and values(r=1).The value for normal women samples (n=52) was 43.2 -513.1 mIU/L, normal men samples（n=68） was 54.8 -334.3 mIU/L.