OBJECTIVE： To explore short-term efficacy and safety of early use of high-dose， medium-dose and low-dose amino acid in premature babies. METHODS： 99 premature babies were selected and randomly divided into high-dose group， medium-dose group and low-dose group， with 33 cases in each group. 3 groups were given Amino acid injection， ivgtt， within 24 h after birth， high-dose group was given 3 g/（kg·d）， medium-dose group 2 g/（kg·d） and low-dose group 1 g/（kg·d）； those dose increased by 0.5 g/（kg·d） day by day； predicted peak values of them were 3.5， 3.5 and 3 g/（kg·d）， respectively. Treatment courses of 3 groups lasted for 28 d. Health indexes， renal function indexes and blood indexes  were observed in 3 groups. The occurrence of complications and ADR were recorded in 3 groups. RESULTS：  2 cases withdrew from high-dose and low-dose groups. Hospitalization stay， the time of body weight increasing to 2 500 g and the rate of body weight decreasing in high-dose group were significantly lower or shorter than in medium-dose and low-dose groups； the medium-dose group was significantly lower or shorter than the low-dose group， with statistical significance （P＜0.05）； the levels of creatinine， residual alkali， serum total bilirubin in high-dose group were significantly higher than medium-dose and low-dose groups， and the medium-dose group was significantly higher than the low-dose group， with statistical significance （P＜0.05）. The number of complications cases in high-dose group （11 cases） were significantly lower than in medium-dose group （20 cases） and low-dose group （26 cases）， with statistical significance （P＜0.05）. No obvious ADR was found in 3 groups. CONCLUSIONS： High-dose of amino acid intravenous nutrition support in early stage can promote the recovery of nutrition state and healthy constitution in premature babies with good tolerance and safety.