PURPOSE: A composition of an agent for treating osteoporosis is provided to suppress bone absorption and to promote bone formation. CONSTITUTION: A composition of an agent for treating osteoporosis contains ethanol solution extract or ethanol extract of horse bone as an active ingredient. The ethanol solution contains 60-80% or 70-80% of ethanol. The composition is a pharmaceutical composition. The pharmaceutical composition is administered by oral or parenteral method. The composition is a food composition and food composition is a functional beverage.본 발명은 골다공증 개선제 조성물을 개시한다. 구체적으로 본 발명은 말뼈 추출물을 유효성분으로 하는 골다공증 개선제 조성물을 개시한다.