Sirolimus　can　inhibit　osteoclastogenesis.　But　sirolimus-activated　autophagy　is　a　favorable　factor　for　osteoclastogenesis.　This　study　aimed　to　explore　the　significance　of　autophagy　in　sirolimus-regulated　osteoclastogenesis.　Our　results　confirmed　that　sirolimus　inhibited　osteoclastic　differentiation　(including　the　number　and　size　of　osteoclasts　as　well　as　the　expression　of　osteoclastic　genes)　and　promotes　osteoclast　precursor　(OCP)　autophagy　(including　LC3　conversion　and　autophagosome/autolysosome　formation).　As　expected,　OCP　autophagy　(including　LC3　conversion　and　LC3-puncta　formation)　promoted　by　sirolimus　was　reversed　by　autophagy　inactivation　with　3-MA　or　Atg13　silencing.　Importantly,　compared　with　single　intervention　of　sirolimus,　the　combination　of　sirolimus　and　3-MA　or　Atg13　silencing　more　effectively　inhibited　osteoclastic　differentiation　and　OCP　proliferation.　In　vivo　experiments　also　demonstrated　that　the　combination　of　sirolimus　and　Atg13-silencing　adeno-associated　viruses　(AAVs)　was　more　effective　than　sirolimus　alone　in　improving　decreased　bone　density　and　damaged　bone　microstructure　(including　Micro-CT　imaging　results,　bone　tissue　parameters　and　trabecular　area),　and　attenuating　osteoclastic　activity　(including　the　abundance　of　osteoclasts　in　trabecular　bones　and　the　production　of　osteoclastic　markers　in　serum)　in　ovariectomized　(OVX)　mice.　In　conclusion,　repressing　Atg13related　autophagy　can　effectively　enhance　the　function　of　sirolimus　in　inhibiting　osteoclastogenesis　by　counteracting　its　pro-autophagic　activity.　Therefore,　the　combination　of　sirolimus　and　Atg13-targeting　therapy　is　expected　to　enhance　the　efficacy　of　sirolimus　in　ameliorating　osteoclastic　osteoporosis.