Objective To determine the incidence of and risk fact ors for retino pathy of prematurity (ROP) among preterm infants in Beijing after implementation of the ROP guidelines. Methods The preterm infants with birth weight le; 2000 g or gestational age le; 3 4 weeks who were admitted to the neonatal intensive care units in 6 hospitals in Beijing from Jan. 1, 2005 to Dec. 31, 2005 were screened. Ophthalmologic examin ations started 3-4 weeks after birth and ROP was classified by the revised Inte r national Classification. Maternal and perinatal risk factors of occurrence of R OP were analyzed. Results In the 639 infants who had been scre ened in the 6 ho spitals, ROP was detected in 69 (10.8%), in whom 23 infants (39 eyes) (3.6%) had type 1 ROP and underwent photocoagulation. The lower the birth weight and small er the gestational age was, the higher the incidence of ROP was. Logistic regres sion analysis indicated that low birth weight, apnea gt;20 seconds, anemia, hypoxic-ischemic encephalopathy and placenta abruption were the high risk factor of R O P.Conclusion In Beijing the incidence of ROP is 10.8% after i mplementation of the ROP guidelines. Low birth weight, apnea gt;20 seconds, anemia, hypoxicischem ic encephalopathy and placenta abruption were the high risk factor of ROP.