Abstract: Objective To evaluate the effect of non-nutritive sucking (NNS), oral massage (OM) and combination method (NNS + OM) on oral feeding in preterm infants, to evaluate whether the combination method is superior to separate usage.Methods The preterm infants (n=120) were randomly assigned to four groups (NNS, OM, NNS + OM and non intervention group, n=30/each group). The NNS group received non-nutritive sucking by a pacifier before nasal feeding for 5 minutes each time, 8 times per day. The OM group received stroking of the oral structure 20 minutes before nasal feeding for 5 minutes each time, once per day. The NNS + OM group received both of the above methods. The non intervention group received standard care without oral interventions. The results of feeding transition time, feeding efficiency, feeding effectiveness, weight gain, and hospitalization time of the four groups were compared.Results There was no difference in feeding transition time between the three intervention groups (P> 0.05). Howevere, the feeding transition time was significantly reduced in three intervention groups compared with that in non intervention group (P<0.05). The feeding efficiency and feeding effectiveness of the three intervention groups were higher than that of the non intervention group when initiated oral feeding (P< 0.05). Feeding efficiency and effectiveness in NNS + OM group was only better than that in non-intervention group when complete oral feeding (P< 0.05). Compared with NNS + OM group and oral massage group, feeding efficiency and effectiveness in NNS + OM group were not statistically significant (P> 0.05).Conclusion Non-nutritive sucking, oral massage and the combination method can promote oral feeding in preterm infants, shorten feeding process, improve feeding efficiency.The effect of combination method was more obvious. Compared to non-nutritive sucking and oral massage, the two combination method showed no obvious advantages.