The experiment was conducted to evaluate the effects of Tremella fuciformis Berk spore fermentation (TSF) and the combination of TSF and porcine growth hormone releasing factor (pGRF) on growth, part immune indices and intestinal microflora in weaned piglets and the comparison with the effect of antibiotics. Forty-eight (28±2) d weaned D×L×Y piglets were randomly allocated to 4 groups with 6 replicates of 2 piglets according to gender and body weight, which were control group fed basal diet, antibiotics (kitasamycin 40 mg/kg+kangdisu sulfas 20 mg/kg), TSF (4 000 mg/kg) and TSF（4 000 kg/kg） combination with intramuscular injection of 1 mg pGRF into hind leg at the beginning of the trial. The experiment lasted for 28 d. The results showed that, compared with control group, both TSF and antibiotics supplementation significantly improved ADG and decreased F/G (P<0.05). The piglets diet supplemented with TSF and TSF+pGRF demonstrated a higher T lymphocyte transfer ratio (P<0.05), serum IL-2 (P<0.05) and classical swine fever antibody titer compared with control group and antibiotics group. Meanwhile, the number of T lymphocytes was also improved (P=0.10). Two TSF supplement groups significant increased the number of intestinal Lactobacillus and Bifidobacterium in piglets compared with antibiotics group (P=0.05), but had no difference with control group (P=0.07). In conclusion, TSF supplementation had the same effects on promoting growth performance as antibiotics, and TSF could effectively improve the immune and optimize the intestinal microflora in weaned piglets. The combination of pGRF and TSF showed a tendency of further improving growth but had no impact on immune and intestinal microflora in weaned piglets.［Chinese Journal of Animal Nutrition, ２００9，２1(5):777-783］