The present invention relates to a composition containing beta-glucan as an effective ingredient for prevention and treatment of osteoporosis. The above captioned beta-glucan is preferably the beta-1.3/1.6 glucan having a lactic acid as a substituent and this beta-1.3/1.6 glucan is preferably produced from Aureobasidium pullulans SM2001(KCCM 10307).