Objective To observe the long-term effectiveness of tendon allograft to repair tendon defect. Methods Between October 1996 and September 1999, 24 patients with tendon defect were treated with tendon allograft which was cultured with deoxyguanosine and preserved at low-temperature or ultra-deep-low-temperature. There were 19 males and 5 females, aged from 12 to 46 years with an average of 25.9 years. These patients included 7 cases of total extensor tendon defect of 2nd-5th fingers, 7 cases of index finger extensor tendon defect, 3 cases of deep flexor tendon defect of 2nd- 5th fingers, 1 case of ring finger deep flexor tendon defect, 3 cases of long extensor tendon defect of 2nd-5th toes, 2 cases of long extensor hallucis tendon defect, and 1 case of shoulder adduction missing. The sizes of tendon defect ranged from 5 to 15 cm. The mean time from injury to operation was 1.3 months (range, 2 hours to 3 months). Results Incisions healed by first intention. No deep infection, infectious diseases, and obvious immune rejection occurred. All patients were followed up from 10 to 12 years with an average of 10.8 years. When compared with contralateral sides, at 10 years of follow-up, 1 patient lost 6-10° flexion function; after 10.6 years, flexion tendon releasing was performed; allografted tendon had normal color and elasticity with decreased diameter and with mild and moderate adherence; and after releasing, function was improved. According to Hand Surgery Association assessment standard, the results were excellent in 12 cases, good in 6, and poor in 6; the excellent and good rate was 75%. Conclusion Tendon allograft which is cultured with deoxyguanosine and preserved at low-temperature or ultra-deep-low-temperature is safe to use in cl inical, which has good long-term effectiveness in treating tendon defect.