Objective To explore the influence of earlier nasal continuous positive airway pressure(NCPAP) applying on pulmonary function,and evaluate the clinical results of the early application of NCPAP.Methods Ninety newborn infants with pulmonary dynspnea treated with face mask from Jan.2000 to Nov.2002 were selected as control group.One hundred and ten patients treated with NCPAP from Dec.2002 to Dec.2006 were selected as treatment group.Treatment group applied KD-300 CPAP oxygen therapy equipment NCPAP delivering oxygen.Setting up and adjusting parameter: the beginning flow volume 6-8 L/min,the oxygen therapy bulk(FiO2)30%-50%,the NCPAP pressure was 0.195-0.488 kPa,parameter was adjusted according to the sickness and detecting the transcutancous oxygen saturation(TcSO2).If nasal cannulae Oxygen therapy couldn′t keep the TcSO2 in 85%-93%,the patients in control group were used face mask,small face mask,the oxygen flow vo-lume was 6 L/min,three holes,average FiO2 was 59%.The artery blood oxygen partial pressure [pa(O2)],artery blood carbon dioxide partial pressure [pa(CO2)],oxygenation index(OI),respiration rate(RR) of 2 groups after therapy 4,24 and 72 h were observed,also the difference of recovery rate between the 2 groups were analyzed.Results Compared with the control group,pa(O2) and OI after the application of NCPAP in treatment group were obviously improved(Pa