Abstract: The effects of yeast β-glucan on production performance and eating behavior of lambs weaned at 28 days of age were investigated. A single factor experimental design was used and fifty lambs (Gansu meat sheep new breeding population, male∶female ratio=6∶4 for better homogeneity) were randomly allotted to 5 groups with 10 replicate lambs in each group. Lambs in group A were fed basal diets, while those in groups B to E were fed basal diets supplemented with 37.50, 75.00, 112.50 or 150.00 mg/kg yeast β-glucan. The final weights (P<0.05) and average daily gain (ADG) (P<0.05) of lambs fed diets with 37.50, 75.00 and 112.50 mg/kg yeast β-glucan were significantly higher than those of group A after-91 days. The ADG of lambs fed a diet with 150.00 mg/kg yeast β-glucan was higher than in the control group after 15-28 days (P=0.088). The final weights (P<0.05) and ADG (P<0.01) of lambs fed a diet with 112.50 mg/kg yeast β-glucan were significantly higher than those of group A after 29-42 days and after 43-56 days respectively. The ratio of feed to gain (F/G) of lambs fed a diet with 112.50 mg/kg yeast β-glucan was significantly lower than that of group A at 43-56 days (P<0.01). The final weight (P<0.01) and ADG (P<0.01) of lambs fed diets with 37.50 and 75.00 mg/kg yeast β-glucan after 57-70 days and 71-91 days, were significantly higher than those of group A although the F/G ratio was significantly (P<0.01) lower. The ruminating times of lambs treated with 112.50 mg/kg yeast β-glucan was higher than those of group A after 55-56 days and after 90-91 days (P<0.05, P<0.01). The ruminating time of lambs treated with 75.00 mg/kg yeast β-glucan was significantly (P<0.01) higher than those of group A after 55-56 days and after 90-91 days. Compared with group A, groups B to E had benefited more, with 81.33, 94.71, 85.10 and 24.17 Yuan/lamb respectively. The optimum diet for early-weaned lambs was a supplement of 75.00 mg/kg yeast β-glucan.