Objective: To study the effects of soluble multi-peptide agent,marked “Gu Kang Tai Ling”,derived from bone tissue on rat bone fracture healing.Methods 80 right tibia defects of rats were sawed.The “Gu Kang Tai Ling”were intramuscularly injected to the rats.The quality of the defect healing was investigated continuously and respectively by the defect bone histomorphometry,biomechanics,X-ray film,and bone mineral density(BMD).Results: Under the treatment of the agent,at early stage trabecular bone volume (TBV)ratio increased 24.7%,and osteoblast surface(OBS)26.7%,at late stage mean trabecular healing surface rate(MTHSR)was increased 38.8%,tibia anti-fracture strength 0.4527～1.4350N，and BMD 7.65% compared with the control group.Conclusion: “Gu Kang Tai Ling”can accelerate rat fracture healing and improve the quality of healing.