Abstract: Objective To explore the influence of exogenous lactoferrin on early lymphocyte subsets in very low birth weight infants.Methods During January 2014 to October 2015, 120 very low birth weight infants of NICU were born in Guangzhou Women and Children's Medical Center were include in the study. And they were randomly devided into two groups:the experimental group (LF group) and the control group. Lymphocyte subsets were tested on the first day, 2 weeks and 4 weeks after birth respectively.Results (1) The difference of lymphocyte subsets between the two groups on the first day after birth was not statistically significant (P>0. 05). (2) The level of T-cell、helper T-cells、NK cell and B-cell in LF group were higher than those in control group at 2 and 4 weeks after birth (P< 0. 05). (3) The level of suppressor T-cell in the LF group were lower than that in control group at 2 and 4 weeks after birth (P< 0. 05). (4) The level of T-cell, helper T-cells, NK cell and B-cell in the two groups all gradually increased along with time increased, whereas the absolute value of suppressor T-cell decreased along with time increased.Conclusion The number of immune cells in very low birth weight infants is low at birth, but increasing with age increasing. Exogenous lactoferrin can promote the maturation of cellular immunity and humoral immunity in very low birth weight infants.