Abstract: Objective: To explore the effect of pulmonary surfactant(PS) on hyaline membrane disease(HMD) of newborn.Methods: PS was administered to seventeen neonates with HMD,then the changes of clinical manifestation,the parameter of mechanical aeration,the results of blood gas and the X-ray presentations of the lung were observed.Results: After medical treatment,the symptoms and signs of the neonates were improved.The pressure peak of mechanical aeration parameter(PIP),positive breath pressure(PEEP),average gas trace pressure(MAP) and breath frequency(RR) dropped remarkably(P<0.05-P<0.01).The level of PaO₂ and pH increased obviously(P<0.05 and P<0.01),and the level of PaCO₂ decreased greatly(P<0.01).At 24 hours after treatment,the X-ray presentations improved significantly.Conclusions: PS therapy can improve the pathological changes of HMD,reduce the time of respirator utilization,the time of hospital stay and the fatality rate.