Objective To explore the effect and feasibility on air oxygen mixing instrument by preventings retinopathy of prematurity(ROP) in preterm infantsmeasures. Method A total of 117 preterm infants of test group were used air oxygen mixing instrument in oxygen inhalation,undergone indirect funduscopic examinations two weeks after birth,and then they were followed-up,the outcome were compared with control group(n=95) of no intervention. Results A total of 212 cases of premature infants,8 cases occurred in ROP,accounted for 3.77%,5 males and 3 females.3 cases were ROP Ⅰstage,4 cases were ROP Ⅱ stage,and 2 case were ROP Ⅲ stage.Among the 8 cases,2 cases in test group and 6 cases in control group,the incidence of ROP was obviously different between two groups(P<0.01).High risk factor analysis showed that neonatal asphyxia,apnea,hyaline membrane disease,severe infection,pneumorrhagia,gestation age,birth weight,concentration of oxygen inhalation,time of oxygen inhalation and mechanical ventilation were significantly related to ROP(P<0.01). Conclusion Using air oxygen mixing instrument in oxygen inhalation can depress the incidence of ROP in preterm infants,the development of ROP is higher in the preterm infants with more complications,higher oxygen concentration and longer mechanical ventilation time.