Objective To compare the effect of ultrasound guided intra-amniotic cavity and fetal lung injection of pulmonary surfactant(PS) to prevent lung injury in premature rabbits. Methods Fifteen pregnant New Zealand rabbits were randomly divided into fetal lung injection PS group (L group)

amniotic cavity injection PS group (A group) and control group(each n=5).On the 27th day of pregnancy

rabbit fetuses were removed through cesarean section 1 hour after injection. The survival time of premature rabbits

the content of dipalmitoyl phosphatidylcholine (DPPC) and interleukin-6 (IL-6) in bronchoalveolar lavage fluid ware detected. The lung tissues were taken for morphological and biochemical analysis.Result Compared with control group

the survival time of premature rabbits in L group and A group was significantly prolonged

the content of DPPC and SP-A increased

the apoptosis index of lung tissue and the pathological score of lung injury and IL-6 decreased(P＜0.05). The lamellar bodies of type II alveolar epithelial cells were increased and the swelling of endoplasmic reticulum was decreased. Compared with A group

the content of DPPC、SP-A and IL-6 in preterm rabbits of L group was increased (P ＜0.05)

and there was no significant difference in the remaining indicators. Conclusion Both intra-amniotic and fetal lung injection PS can effectively prevent lung injury in premature rabbits. Compared with PS injected into amniotic cavity

PS injection into fetal lung with the same amount can obtain greater benefits

which is expected to be a new treatment to prevent lung injury in premature infants.