Abstract: OBJECTIVE To evaluate the rationality of the postoperative DVT prevention with the application of low molecular weight heparin over a period of time. METHODS Cases were collected with orthopedics surgery within a year, divided them into joint replacement, internal fixation and post-traumatic spinal prosthesis. Statistics was done according to the use of LMWH, delivery time, course of treatment and prevention effect. RESULTS Utilization rate of LMWH was 84.0%, post-traumatic spinal prosthesis was 58.5% which was below the average. Preoperative 12 h dosing rate of joint replacement, internal fixation and spina repairation were 7.5%, 33.3% and 0%, respectively. Whole quantity dosing rate 12 h after operation were 87.5%, 31.6%, 8.3%, respectively. Between joint replacement and internal fixation, the course of drug treatment was more than 35 d, the incidence of DVT was 12.4%. CONCLUSION The utilization of LMWH can’t follow the guidelines. This is an important reason why the incidence of postoperative DVT is still high in drug prevention.