Objectives : This study was designed to investigate the effects of horse bone powder extract on the growth of longitudinal bone in adolescent male rats. Methods： Longitudinal bone growth was measured by fluorescent microscopy. To examine the effects on the growth plate metabolism, the total height of growth plate, the induction of local insulin-like growth factor-1 (IGF-1), and bone morphogenetic protein-2 (BMP-2) were measured. Results： Horse bone powder extract enhanced longitudinal bone growth and total height of the growth plate. Also, it promoted the induction of local IGF-1 and BMP-2 of the growth plate. Conclusions： This study shows that the horse bone powder extract effects longitudinal bone growth in adolescent rats and might be used for both stunted adolescents and inherent growth failure patients.