To treat respiratory distress syndrome,surfactant is currently delivered via less invasive surfactant administration(LISA) or INtubation SURfactant Extubation(INSURE).The aim of this study was to compare the effect of the two delivery methods of surfactant on cerebral autoregulation.Near infrared spectroscopy monitoring was carried out to detect cerebral oxygen saturation(Sc O2),and the mean arterial blood pressure(MABP) was simultaneously recorded.Of 44 preterm infants included,the surfactant was administrated to 22 via LISA and 22 via INSURE.The clinical characteristics,treatments and outcomes of the infants showed no significant differences between the two groups.The correlation coefficient of Sc O2 and MABP(rSc O2-MABP) 5 min before administration was similar in the two groups.During surfactant administration,rSc O2-MABP increased in both groups(0.44±0.10 to 0.54±0.12 in LISA,0.45±0.11 to 0.69±0.09 in INSURE).In the first and second 5 min after instillation,rSc O2-MABP was not significantly different from baseline in the LISA group,but increased in the first 5 min after instillation(0.59±0.13,P=0.000 compared with the baseline in the same group) and recovered in the second 5 min after instillation(0.48±0.10,P=0.321) in the INSURE group.There were significant differences in the change rates of rSc O2-MABP between the two groups during and after surfactant administration.Our results suggest that cerebral autoregulation may be affected transiently by surfactant administration.The effect duration of LISA is shorter than that of INSURE(<5 min in LISA vs.5–10 min in INSURE). To treat respiratory distress syndrome, the surfactant is currently delivered via less invasive surfactant administration (LISA) or INtubation SURfactant Extubation (INSURE). The aim of this study was to compare the effect of the two delivery methods of surfactant on cerebral autoregulation. Near infrared spectroscopy monitoring was carried out to detect cerebral oxygen saturation (Sc O2), and the mean arterial blood pressure (MABP) was recorded. If 44 preterm infants included, the surfactant was administrated to 22 via LISA and 22 via INSURE.The clinical characteristics, treatments and outcomes of the infants showed no significant differences between the two groups. correlation coefficient of Sc O2 and MABP (rSc O2-MABP) 5 min before administration was similar in the two groups. both groups (0.44 ± 0.10 to 0.54 ± 0.12 in LISA, 0.45 ± 0.11 to 0.69 ± 0.09 in INSURE). In the first and second 5 min after instillation, rSc O2-MABP was not significantly different from baseline in the LISA group, but increased in the first 5 min after instillation (0.59 ± 0.13, P = 0.000 compared with the baseline in the same group) and recovered in the second 5 min after instillation (0.48 ± 0.10, P = 0.321) in the INSURE group. There were significant differences in the change rates of rSc O2-MABP between the two groups during and after surfactant administration. Our results suggest that cerebral autoregulation may be transiently by surfactant. The effect duration of LISA is shorter than that of INSURE (<5 min in LISA vs. 5-10 min in INSURE).