OBJECTIVE: To observe the therapeutic effect of electro-acupuncture on tendon healing and functional recovery of rotator cuff injury in rats and explore the therapeutic mechanism of electro-acupuncture. METHODS: Ninety SD rats were randomly divided into electro-acupuncture group, model group and blank control group, and models of rotator cuff injury were established in the former two groups.The rats in electro-acupuncture group was treated with electro-acupuncture after the operation, and those in the other two groups received no treatment.The right forefoot thermal withdrawal latency (TWL), the contents of IL-1β, IL-6 and TNF-α in the synovial fluid and the maximum tension load of supraspinatus tendon were measured at 2, 4 and 8 weeks after the operation. RESULTS: TWL in the model group was significantly lower than that in the blank control group and electro-acupuncture group at 2, 4 and 8 weeks after the operation ( < 0.05).At all these time points, the contents of IL-1β, IL-6 and TNF-α in the synovial fluid were significantly higher in the model group than in the blank control group and electro-acupuncture group ( < 0.05).At 2 weeks, the maximum load in electro-acupuncture group and model group were significantly lower than that in the blank control group ( < 0.05).At 4 and 8 weeks after the operation, the maximum pull load was significantly greater in electro-acupuncture group than in the model group ( < 0.05). CONCLUSIONS: Electro-acupuncture treatment not only effectively reduces the expression of inflammatory factors to relieve pain, but also promotes the repair of damaged tissue to improve the biomechanical properties of rotator cuff in the rat models.