Objective To assess survival rates and major complications of extremely preterm infants( EPI) discharged from the hospital,in order to provide some evidence for the treatment of such cases in the future. Methods A retrospective study Was performed by revieWing the clinical data of 299 infants at gestational age(GA)﹤28 Weeks Who Were admitted at the Neonatal Intensive Care Unit( NICU)of Tianjin Central Hospital of Gynecology Obstetrics from January 1st 2011 to December 31st,2017. The survival rates and major morbidities of EPI according to different GA Were compared by trend Chi－squaΥe and t test. Results A total of 299 cases of EPI Were included in the study,With a mean GA of 26. 5 Weeks(22 +3 －27 +6 Weeks)and mean birth Weight of 958. 5 g(360－1 550 g). From 2011 to 2017, the number of hospitalized EPI increased gradually( from 21 cases in 2011 to 79 cases in 2017),especially in EPI of loWer GA(GA﹤25 Weeks)Which increased from 4 cases in 2011－2014 to 26 cases in 2015－2017. The rates of sur﹣vival infants With GA﹤28 Weeks Were 78. 6%(235／299 cases),including 18. 2%(2／11 cases)at GA≤23 Weeks, 52. 6%(10／19 cases)at 24 Weeks,75. 8%(25／33 cases)at 25 Weeks,78. 5%(62／79 cases)at 26 Weeks and 86. 6%(136／157 cases)at 27 Weeks,respectively,Which shoWed that survival rates increased With the groWth of GA( χ2 ﹦31. 3,P﹦0. 000). Major morbidities among the survival infants Were severe retinopathy of prematurity(ROP,stageⅢor above according to international classification and received treatment)[16. 2%(38／235 cases)],bronchopulmonary dysplasia(BPD,supplemental oxygen use at a postmenstrual age of 36 Weeks)[15. 3%(36／235 cases)],late－onset sepsis(LOS)[24. 7%(58／235 cases)],intraventricular hemorrhage(IVH),grade 3 or 4)or periventricular leukoma﹣lacia(PVL)[9. 4%(22／235 cases)],necrotizing enterocolitis(NEC),stage≥Ⅱof Bell,criteria)[3. 0%(7／235 cases)],and decreased With increased gestational age(χ2 ﹦18. 450,19. 773,15. 024,all P﹦0. 000). Rates of ROP, BPD and LOS in EPI With GA﹤25 Weeks Were 41. 7%(5／12 cases),58. 3%(7／12 cases)and 66. 7%(8／12 cases), respectively,Which Were much higher than those of EPI With GA 25－28 Weeks[14. 8%(33／223 cases),13. 0%(29／223 cases),22. 4%(50／223 cases)](all P﹤0. 05). Conclusions From 2011 to 2017,the number of hospitalized EPI increased gradually and the rate of survival rose With every 1－Week increase in GA,While major morbidities Were reduced accordingly. EPI of GA﹤25 Weeks had a greater risk of mortality and major morbidities.