Abstract: [Abstract] Objective To research the effect of Mesenchymal Stem Cells（MSCs）on tendon-bone healing in bone tunnel . Methods Anterior cruciate ligament reconstruction with semitendonous tendon was done in knee joints of New Zealand rabbits by suspend fixation model. Mesenchymal Stem Cells were implanted in bone tunnel in experimental group and only operation in control group. Specimens were collected 4 weeks, 8 weeks and 12 weeks after surgery. Sections were stained with HE, MASSON . Special changes of interface tissue between bone tunnel and tendon graft were observed and informations of healing between tendon and bone tunnel were analyzed. Results In MSCs group abundant penetrating Sharpey fibers were appeared at 8weeks and Sharpey fibers were appeared at 12 weeks in control group，direct connection can be seen in MSCs group. Conclusion MSCs can accelerate tendon healing in bone tunnel.

Key words: Mesenchymal Stem Cells, Tendon graft, Bone tunnel, Healing