Background: The amino acid glutamine plays an important role in maintaining functional integrity of the gut. In addition, glutamine is utilized at a high rate by cells of the  immune  system.   In  critically  ill  patients,  glutamine  is  considered  a conditionally essential amino acid. However, very-low-birth-weight (VLBW) infants are susceptible to glutamine depletion as nutritional supply of glutamine is limited in the first weeks after birth. In one hand, administration enteral nutrition of VLBWIs is limited by immaturity of their gastrointestinal tracts. In another, glutamine can not be provided by standard intravenous amino acid solution. So we can suppose that glutamine supplementation may improve outcome in VLBW infants. Methods: VLBW infants who were charged in from Mar. 2005 to Feb. 2006 with birth  weight   <1500g   were   randomly  allocated  to   receive   enteral   glutamine supplementation (0.3g/Kg/day) or standard enteral feeding. Primary outcome was feeding tolerance, which defined as time to full enteral feeding (a feeding volume ≥ 120 ml/Kg/day). Furthermore, incidence of serious infections and short-term outcome were evaluated. Spontaneously, plasma concentrations of glutamine, IL-6 and IL-8 were measured at three time points: at days 1, 7 and 14 of life. Result:   At  last,   58   infants  were  enrolled  in  the  study;   30  infants  in the glutamine-supplemented  group and 28  in the  control  group.  There were no significant differences in baseline patient characteristics between the two groups. Enteral glutamine supplementation in VLBW infants may reduce the time to achieving full enteral feeding and the incidence of serious infections was lower in glutamine group. But the time to regain birth-weight and subsequent weight gain were similar in the two groups. And plasma concentrations of glutamine, IL-6 and IL-8 were not different, either.