I. The main goal in the early post-operative period after ACL surgery is to restore the range of motion of the knee and strengthen the muscles. Ankle pump, mainly to prevent blood clots, is important. It lasts 6-8 weeks. Flexion exercises once a day, do not repeat multiple exercises. Aim for daily progress in knee flexion angle. For patients undergoing ligament reconstruction alone, 90 degrees should be achieved within four weeks at the slowest. Apply ice for 20 minutes immediately after the exercise. Knee extension exercises, starting on the first postoperative day. Continue for 4-6 weeks. Muscle strength exercises with a straight leg raise. The straight leg raise is important and needs to be focused on throughout the rehabilitation cycle. after 10 weeks, perform static squat exercises as appropriate. Patients with ACL reconstruction alone can walk with weight on the ground (i.e., the affected limb can step on the ground) the day after surgery to meet simple activities of daily living. In patients with combined cartilage injury, meniscectomy or suture, weight-bearing ambulation is delayed as appropriate (i.e., the affected limb is not allowed to step on the ground). Note that walking is not a muscle strength exercise. Second, the recovery exercise time 1. 3 months after surgery can jog, but each running distance should not be more than 200 meters, slow speed, can not use explosive force; 2., strenuous exercise to be more than six months after surgery. The muscle strength of the thigh on the side of surgery is close to the normal leg muscle strength; 3., If you are not an athlete, without systematic and comprehensive rehabilitation training, individuals are not recommended to carry out sports too early. Pay attention to gradual progress and avoid sprains. Strenuous exercise is best for more than 10 months. III. Follow-up time 2 weeks, 6 weeks, 12 weeks, 6 months, before resuming strenuous sports, 1 year, 2 years, 3 years …………….