Objective To explore the clinical significance in combined detection of C-reactive protein and the cervical secretion smear in chorioamnionitis with preterm premature rupture of membranes (PPROM).Methods Eighty patients with PPROM (PPROM group) were selected and divided into chorioamnionitis group (n =55) and without chorioamnionitis(n =25) according to the diagnosis.The levels of C-reactive protein and cervical smear were analysis,including sensitivity,specificity,positive predictive value and negative predictive value.Sixty cases of preterm no premature rupture of membranes pregnant women with the same gestational age were chosed as the control group.Results The positive rate of CRP and cervical secretions smear in PPROM group were higher than those of control group,and the differences were statistically significant (x2 =50.24,54.81 ;P ＜ 0.05).The sensitivity,specificity,positive predictive value and negative predictive value by the CRP diagnosis of chorioamnionitis in patients with PPROM were 58.18％,63.64％,36.00％,32.00％ respectively.Those indices of cervical secretions smear diagnosis were 66.67％,67.31％,29.03％,28.57％ respectively.The sensitivity,specificity,positive predictive value regarding of CRP and cervical secretions smear joint inspection diagnosis of chorioamnionitis were 69.09％,88.00％,92.68％,56.41％ respectively.Conclusion The inspection of CRP combined with cervical secretion smear can improve specificity and positive predictive value of chorioamnionitis diagnosis with PPROM pregnant women.