Objective To investigate the method and curative effect of malposed-suture hanging and fastening method of double-lariat lock catch knot in repairing origin of medial collateral l igament (MCL) rupture. Methods From February 2008 to February 2009, 36 patients with acute MCL rupture were treated with malposed-suture hanging and fastening method of double-lariat lock catch knot. There were 21 males and 15 females with an average age of 40 years (range, 17-58 years),including 19 left knees and 17 right knees. Repture was caused by traffic accident in 5 cases, by fall ing in 11 cases, by kicking in 3 cases, by crush in 4 cases, and by sprain in 13 cases. The X-ray films of double knees at stress state showed the medial joint space of affected knee joint increased 6.5-13.5 mm (11.2 mm on average) when compared with that of normal knee joint. The time from injury to operation was 36 hours to 8 days (3.5 days on average). Results All wounds healed by first intention. Thirty-one cases were followed up 12-20 months (15 months on average). No compl ication of wound infection, deep venous thrombosis, and l igament rerupture occurred. The medial joint space of affected knee joint increased 1.5-5.6 mm (3.5 mm on average) when compared with that of normal knee joint. According to Lysholm assessment standard, the results were excellent in 20 cases and good in 11 cases, the excellent and good rate was 100%. Conclusion Repair of origin of MCL with malposedsuture hanging and fastening method of double-lariat lock catch knot has advantages of less injury, rel iable fixation, and rapid recovery of knee stabil ity.