The effects of zinc on collagen synthesis and wound healing were observed in 124 rats. The animals were divided into three groups. ZD--zincdeficient, SP--pair fed with zinc supplemented and SF---ad lib withzinc supplemented, each receiving 0.07, 0.82 and 0.84 mg Zn per rat per day respectively. An 8 cm long surgical incision was made on one side of the back of each animal and 3 pieces of sponge were implanted subcutaneous^ on another side. The results showed that the rats receiving zinc supplement (SP , SF) had greater increase of body weight and higher concentration of serum zinc than the ZD rats before and after operation, Tke fibroblast counts in granular tissues of group ZD were significantly less than that of groups SP and SF from the 4th to 14th day after operation. The breaking strength of healing incision of groups S P and SF was greater than that of group ZD in the late stage of wound healing. The determination of sponge collagen indicated that groups SP and SF had stronger ability to synthesize collagen after being wounded than ZD animals. The results suggested that zinc might play an important role in wound healing, not only due to the increase of diet intake, but also due to increased fibroblast proliferation and collagen synthesis.