Abstract: A one-factorial trial arrangement including five lysine levels(0.60%,0.80%,1.00%,1.20%,1.40%) was conducted to study the effect of lysine intake on growth performance and pancreatic endocrine function of early weanling piglets. Fifty-five 21-day-old male early weanling piglets were allotted randomly to five groups, each of which was fed one of five experimental diets containing different lysine levels for twenty-one days. At the end of the trial, five piglets from each group were infused with glucose solution and blood samples were collected at different time after the infusion. The results of this experiment demonstrated that there was significant positive correlation between lysine intake and daily weight gain in early weanling piglets(P＜0.05); according to the growth performance, the lysine requirement of weanling piglet from 21-day to 42-day of age was no less than 3.16 g/day or 1.4% of the diet; the levels of insulin in serum decreased significantly when piglets were fed lysine-deficient diet(P＜0.05).