To evaluated the inhibition effect of local injection of odanacatib on orthodontic relapse.Thirty rats were randomly divided into 2 groups(n =15).The maxillary right first molars of all animals were subjected to orthodontic force and moved mesially.Three weeks later,the force was removed,and the teeth relapsed.The rats of experimental group were received local injections of odanacatib.The control group received saline instead.Tooth movement and relapse were measured when appliances removed after 0 day and 2 weeks.The rats were sacrificed after the 2-week relapse.The microcomputed tomography analysis was performed to quantify the alveolar bone,and the values of bone mineral density(BMD) and bone volume fraction(BVF) were measured.The percentage of relapse in the experimental group was significantly lower than that in the control group(P ＜0.05),and the BMD and BVF of alveolar bone in the experimental group were significantly higher than those in the control group(P ＜0.05).Local injection of odanacatib effectively inhibit the relapse after orthodontic tooth movement in rats.