Abstract: Objective: To explore the clinical application value of the respirator parameters regulated by the difference of pulmonary alveoli-artery oxygen pressure in children with severe pneumonia.Methods: One hundred and eight children with severe pneumonia were randomly divided into the observation group and control group(54 cases each group),the patients were diagnosed and treated supportively.The control group and observation group were treated with common respirator and respirator with the parameter regulated by the difference of pulmonary alveoli-artery oxygen pressure,respectively.The treatment efficacy and clinical manifestation between two groups were compared.Results: During the 1 to 24 h of mechanical ventilation,the PaO₂ levels in observation group was significantly higher than that in control group(P<0.01),and the difference of the PaCO₂ level between two groups was not statistically significant(P>0.05).The ventilation time,pH and oxygenation index in observation group were significantly higher than those in control group(P<0.01).The total effective rates in observation group and control group were 92.59% and 70.37%,respectively,the difference of which was statistically significant(P<0.01).Conclusions: The respirator parameter regulated by the difference of pulmonary alveoli-artery oxygen pressure can improve the treatment efficacy,and reduce the complication and mortality of patients.