Semaphorin 3A(Sema 3A)is a member of the signaling family.It is involved in axon guidance,cardiovascular development,tumor formation,regulation of immune cells,and bone homeostasis.NRP-1 plays a role as its co-receptor.In recent years,research has found that the Sema 3A/NRP-1 pathway promotes bone formation,inhibits bone resorption,and regulates bone metabolism.Specifically,it regulates bone metabolism through the classic Wnt/β-catenin signaling pathway,sGC-cGMP signaling pathway,neuromodulation,RANK-RANKL pathway,inflammatory response regulation,and other pathways.We review the relevant literature both domestically and internationally in recent years,with the aim of providing reference for the prevention and treatment of OP.