This experiment was selected a β-glucan producing mushroom strain and developed industrial media, and used to β-glucan as an alternative for antibiotics in weaned pigs. Yields of mycelial biomass and extracellular β-glucan from Youngji (Ganoderma lucidum) mushroom was 8.52g/L and 4.49g/L respectively. Also, we prepared optimum formula for mushroom cultivations. A total of 144 pigs (8.6±0.9 ㎏ average body weight, weaned 20±3 days of age) were allotted to 4 different treatment groups and replicated 4 times with 8 pigs per replicate in randomized complete block design. Treatments were T1) NC (negative control, basal diet), T2) PC (positive control, basal diet+0.255% antibiotics), T3) NC+0.2% β-glucan and T4) PC+0.2% β-glucan. The T2 and T4 treatments were significantly higher in feed efficiency by antibiotics group (p＜0.05), however, there was no significant differences in terms of average daily gain (ADG) and average daily feed intake (ADFI) during phase Ⅰ(0~14 days). In phase Ⅱ(15~28 days), Pigs fed with antibiotics and β-glucan (T4) had greater ADG than other treatments (p＜0.05), while no differences were observed in ADFI and feed efficiency. During the whole experiment period, the ADG of T4 treatment was higher than other treatments. Pigs fed with β-glucan (T3 and T4) had greater diarrhea score and moisture content than other treatments (p＜0.05). Pigs fed with β-glucan (T3 and T4) had greater moisture content than other treatments (p＜0.05). However, there was no significant differences in diarrhea score and mortality of weaned pigs. There was marginal reductions in feed cost measured feed cost per weight gain used in antibiotics and β-glucan added diet during phaseⅠ. In the second phase, the treatment supplemented with antibiotics had a significantly lower feed cost per weight gain compared to the other treatments. The results from these experiments suggests that β-glucan is likely able to improve the growth performance, and reduce feed cost although they do not have similar effects like antibiotics in weaning pigs.