Steroid-related　osteonecrosis　of　the　femoral　head　(ONFH)　may　be　a　disease　that　results　from　the　abnormal　osteogenic/adipogenic　differentiation　of　bone　marrow-derived　mesenchymal　stem　cells　(BMMSCs).　In　the　present　study,　we　examined　the　possible　use　of　lithium　in　an　aim　to　reverse　the　abnormal　osteogenic/adipogenic　differentiation　of　BMMSCs　isolated　from　rats　with　steroid-related　ONFH　(termed　ONFH-BMMSCs).　BMMSCs　obtained　from　steroid-related　ONFH　rat　femurs　were　cultured　with　or　without　lithium　chloride　(LiCl).　BMMSCs　obtained　from　normal　rat　femurs　were　cultured　as　controls.　LiCl　significantly　increased　the　expression　of　osteocalcin　and　Runx2　in　the　ONFH-BMMSCs　during　osteogenic　induction.　The　mineralization　of　ONFH-BMMSCs　following　osteogenic　induction　was　also　enhanced.　Furthermore,　LiCl　exerted　anti-adipogenic　effects　on　the　ONFH-BMMSCs　by　inhibiting　the　expression　of　peroxisome　proliferator-activated　receptor　gamma　(PPAR　gamma)　and　fatty　acid　binding　protein　4　(Fabp4)　during　adipogenic　induction,　and　decreasing　lipid　droplet　formation　at　the　end　of　adipogenic　induction.　These　effects　of　LiCl　on　the　ONFH-BMMSCs　were　associated　with　an　increased　expression　of　beta-catenin　and　a　decreased　expression　of　phosphorylated　GSK-3　beta　at　Tyr-216,　and　these　effects　were　abolished　by　treatment　with　quercetin,　an　antagonist　of　the　beta-catenin　pathway.　The　normal　osteogenic/adipogenic　activity　of　BMMSCs　may　be　impaired　in　steroid-related　ONFH.　However,　as　demonstrated　by　our　findings,　LiCl　reduces　abnormal　adipogenic　activity　and　simultaneously　increases　the　osteogenic　differentiation　of　ONFH-BMMSCs　by　activating　the　beta-catenin　pathway.