Purpose: To Compare tendon-to-bone healing in remnant-preserving and conventional anterior cruciate ligament reconstruction. Methods: 72 New Zealand rabbits were randomly assigned to conventional ACL reconstruction group (group A), remnant-preserving and tensioning ACL reconstruction group (group B), and remnant-preserving and graft through remnant sleeve ACL reconstruction group (group C), with 24 rabbits (48 knees) in each group. The incidence and degree of bone tunnel enlargement in each group were analyzed using CT 3D reconstruction. Graft tendon-bone healing was monitored by HE and Masson staining, and osteoprotegerin (OPG) and receptor activator of nuclear factor kappa B ligand (RANKL) mRNA expression in the bone tissue surrounding the graft. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to evaluate the ratio of OPG/RANKL expression. Results: Histological analysis showed that group C had the best graft tendon-bone healing, followed by group B and group A at all time-points post-surgery. At weeks 3 and 6 post-surgery, OPG mRNA levels and OPG/RANKL values were higher in groups B and C compared to group A (P < 0.05). RANKL mRNA levels of groups B and C were lower than group A (P0.05). At 3 weeks post-surgery, the incidence and degree of bone tunnel enlargement were greater in group A compared to groups B and C (P < 0.05). Conclusion: Both remnant-preserving construction approaches promoted graft tendon-bone healing, the underlying mechanism may be associated with the upregulation of OPG mRNA and downregulation of RANKL mRNA in bone tunnel early post-operation.