Object : Warming acupuncture (WA) has been used in Oriental Medicine for the treatment of physical disabilities caused by ligament damage. Here, the effects of WA on injured ligament tissues were investigated using the rat model. Methods : The rats were induced injury on the right hind ankle, and 4 weeks later, WA was given onto the acupoint GB4O(Quixu) of the injury area on a weekly basis for 6 weeks. Main outcome was measured by levels of Erk1/2. Hoechst nuclear staining and collagen staining in the ligament tissue. Result : Levels of active form of Erk1/2 kinase were increased in the injured ligament with WA compared with the control ligament induced injury only, and this change correlated with cell number increases in the ligament by WA. Type III, but not type I, collagen mRNA and protein levels were elevated in the injured ligament treated with WA. Moreover, histological staining showed increased re-organization of collagen fibers in the ligament by WA. Conclusions : The present data suggest that WA performance to the injured ligament may facilitate the healing process via increasing cellular activity.