OBJECTIVE: This study investigated the life style and health status of preterm and term infants' mothers in order to explore the risk factors for preterm delivery. METHODS: A total of 600 matched cases, including 120 pairs of preterm infants and their mothers and 180 pairs of term infants and their mothers were recruited. All of the mothers participated in a questionnaire survey on life style and health status during or before pregnancy. General data of the infants were also collected. Logistics regression analysis was used for evaluating the risk factors for preterm delivery. RESULTS: The height, body weights and body mass index before pregnancy in preterm infants' mothers were significantly lower than those in term infants' mothers (P<0.05). The birth height and weights and Apgar scores in preterm infants were significantly lower than those in term infants (P<0.05). The whole nutritional Knowledge-Attitude-Practice (KAP) scores in preterm infants' mothers were significantly lower than those in term infants' mothers (P<0.05). Multiple factor regression analysis showed that recurrent abortions before gestation (OR=2.332, P<0.05) and premature rupture of membrane before delivery (OR=7.979, P<0.01) were risk factors for preterm delivery, while maternal nutritional KAP scores (OR=0.949, P<0.01) and body weights before pregnancy (OR=0.954, P<0.05) were protective factors. CONCLUSIONS: The women with low body weight, low nutritional KAP scores or recurrent abortions history before pregnancy or presenting premature rupture of membrane before delivery are at high risk for preterm delivery.