Prematurity is the main cause for respiratory distress syndrome(RDS) in neonates. The goal in the treatment of RDS is to maintain respiration with adequate oxygenation. ETS needs to be performed to remove lung secretions in the ventilated premature infants with RDS. Oxygen saturation(SpO2) and heart rate(HR) were compared in 22 premature infants with RDS using two types of ETS: open ETS versus close ETS. The results showed there was no significant difference in the SpO2 and HR returned to the baseline within 1 minute after suctioning. But in some case, there was a significantly greater incidence in the decrease of SpO2 below 90% occurred in the open ETS than in the close ETS. It implies that closed ETS may be beneficial to premature infants who tend to develop desaturation easily.