Leptin may indirectly suppress bone formation via a central nervous relay and may stimulate bone formation via direct peripheral effect. Leptin' s antiosteogenic function is mediated through the sympathetic nervous system and does not involve pathways with melanocortin and cocaime-amphetamine-regu-lated transcript, which are critical for leptin' s anorexigenic action. Leptin' s actions to modulate bone formation through sympathetic nervous system could suggest new therapeutic approaches for diseases such as osteoporosis. The progress of the relationship between leptin and sympathetic nervous system and bone formation is reviewed.