In order to estimate the occurrence of Preterm Delivery (PD) and factors associated with PD, 1141 perinatal cases at first affiliated hospital were collected by the method of systematic random sampling. The occurrence rate of PD was 6.0%. Multivariate analysis revealed that the history of premature birth, twin pregnancy, polyhydramnios, placenta praevia, premature rupture of fetal membranes and Bart's fetal hydrops were the main risk factors with statistical significance. Path analysis showed that the history of premature birth had indirect positive effect (elevating risk of PD) on PD through premature rupture of the fetal membranes and Bart's fetal hydrops. Similarly, twin pregnancy had indirect positive effect through premature rupture of the fetal membranes and polyhydramnios. It is suggested that proper health care of the pregnant mother attending to the risk factors should be emphasized to prevent the occurrence of PD.