Objective: The research was aimed to show about characteristics of subject, fetal fibronectin, vaginal pH, cervical length of women with threatened preterm labor, and which are become preterm labor? Preterm labor is occurs most often in 20 weeks gestation to less than 37 weeks gestation. This condition is concerned about Obstetric problem and associated with significant neonatal morbidity and mortality.Methods: This study used the design of case control where preterm pregnant women who become research subjects divided into two groups with threat and without the threat of pre-term labor. Fetal fibronectin , vaginal pHand cervical length than in both groups were evaluated as a risk factor for preterm labor. Mann-Whitney test , Wilcoxon test and Chi-squared test were used as statistical tests with a confidence level of 95%.Results: A total of 86 preterm pregnant women involved in this study with an average age 30 , 5 ± 6.25 (group threat) 32.16 ± 5.25 (non-threatening). Comparison of fetal fibronectin (p = 0.005), vaginal PH(p