Objective:To establish the evaluation of the median values for serum free β-human chorionic gonadotropin(β-HCG),pregnancy-associated plasma protein A(PAPP-A)and fetal nuchal translucency thickness(NT)in first-trimester prenatal screening in Nanjing region and investigate the standard program of the cutoff value for clinical soft-marker and its significance in prenatal diagnosis. Methods: The concentrations of β-HCG and PAPP-A in 1 684 gravidas with pregnancy of from 8 to 13+6 weeks were measured by time-resolved fluoroimmunoassay(TRFIA),and fetal NT value in their gestation from 11 to 13+6 weeks was determined by ultrasound scanning. Then the pregnancy outcomes of gravidas were followed up. Results: ① The median values ofβ-HCG in different gestigational week were 32% higher than their embedded parameters of software,those of PAPP-A were close to their embedded parameters in different gestigational week except in the 8th week of pregnancy,and those of NT values were 15% less than their embedded parameters;② when the positive rate of prenatal screening was 5%,the cutoff value of high risk in 21-trisome(Down’s Syndrome)was about 1∶550,and 4 cases with chromosome abnormalities were detected;③ The multiples of the median(MOM)values of serum PAPP-A with adverse pregnancy outcome in first-trimester prenatal screening were significantly lower than those with normal pregnancy outcome, and NT values were markedly higher than those with the normal pregnancy outcome. Conclusion: The standard cutoff values of the median soft-markers in serum and ultrasound scanning may be different in diverse regions,thus it is necessary to further investigate its applicability of the embedded parameters with foreign software;What′s more the MOM value of single soft-marker in first-trimester prenatal screening is important on the pregnancy outcome assessment,and it is benefit to detect other chromosomal abnormalities.