Abstract: Abstract: objective: to study the analysis of the clinical application of fetal protein fiber connection detection in preterm and its value.Methods: randomly selected from our hospital outpatient prenatal or pregnancy, 200 cases of pregnant women in the hospital, through vaginal secretions, fornix after acquisition using rapid detection of fetal protein fiber connections for testing.The other gathering leucorrhea routine detection, bacterial vaginal disease, mycoplasma, chlamydia, and so on.Detailed record delivery situation and ending.Results: 4 cases of a total of 200 cases of pregnant women in childbirth, 7 d 8 cases in 14 d childbirth, 20 cases in 34 weeks delivery, 36 cases in 37 weeks delivery.Sensitivity, specificity, positive predictive value and negative predictive value: 7 d: 100.0%, 78.0%, 7.0%, 78.0%;14 d: 76.0%, 78.0%, 11.0%, 78.0%;34 weeks: 51.0%, 79.0%, 17.0%, 79.0%;37 weeks: 34.0%, 78.0%, 21.0%, 78.0%.Out of 40 cases of preterm pregnant women, a total of 45 cases fFN is positive, 38 cases of reproductive tract infections;115 cases of negative, 25 cases of reproductive tract infections, comparisons difference was statistically significant (P < 0.05).Actual preterm pregnant women 30 cases, 34 weeks pregnant childbirth in 16 cases, 4 cases of birth gestational age less than 28 weeks, the rest of the babies survive.Conclusion: the middle-late fFN detection can effectively prompt premature birth, pregnant women during pregnancy to continue testing for many times, found abnormal after timely diagnosis and treatment.