Objective To explore the effect of early administration of high-dose amino acids in parenteral nutrition for low birth weight infants of prematurity.Methods A total of 191 prematures admitted to the First Affiliated Hospital of Nanjing Medical University from June 2015 to December 2016 were selected,and they were randomly divided into the study group (n =110) and the control group (n =81).The starting amino acid dose was 1.8-2.5 g/(kg · d)and 1.0-1.5 g/(kg · d) in the study group and the control group,respectively.Lipids,glucose,and electrolytes in parenteral nutrition were applied according to standard protocol of the guideline.And the start of enteral feeding,the recovery of birth weight,the duration of parenteral nutrition,the time before total enteral nutrition,duration of hospital stay,incidence of respiratory distress syndrome,duration of mechanical ventilation and incidence of kaliopenia were compared between the 2 groups.Results The start of enteral feeding,the recovery of birth weight,the duration of parenteral nutrition,the time before total enteral nutrition in the study group were earlier than those in the control group [(3.83 ±3.15) d vs.(5.53 ±5.63) d,(15.47±10.54) d vs.(19.47 ± 14.57) d,(16.46 ± 10.33) d vs.(21.41 ±18.00) d,(6.36 ± 4.88) d vs.(8.48 ± 9.27) d],and the differences were all statistically significant (t =2.455,2.097,2.217,2.041,P =0.016,0.038,0.029,0.043).The duration of hospital stay was shorter and the hospitalization expenses were lower in the study group than those in the control group,but the differences were not significant (all P ＞ 0.05).The incidence of respiratory distress syndrome in the study group was significantly lower than that in the control group[20.91％ (23/110 cases) vs.35.80％ (29/81 cases)],and the difference was statistically significant (x2 =5.223,P =0.022).The duration of mechanical ventilation in study group was shorter than that in control [(1.12 ± 2.62) d vs.(3.31 ± 8.13) d],and the difference was statistically significant (t =2.231,P =0.028).The incidence of kaliopenia in the study group was higher than that in the control group [30.91％ (34/110 cases)vs.17.28％ (14/81 cases)],and the difference was statistically significant (x2 =4.603,P =0.032).There were not significant differences in terms of complications of necrotizing enterocolitis,sepsis,extrauterine growth retardation,hospital infection,metabolic acidosis,hyperglycemia,glucopenia,patent ductus arteriosus and respiratory distress syndrome between 2 groups (all P ＞ 0.05).Conclusions Early administration of high-dose amino acids in parenteral nutrition for preterm infants can result in earlier enteral nutrition,shorter parenteral nutrition duration without increasing incidence of complications and hospitalization expenses.