Through the Annexin V-FITC/PI double staining and Western blotting detection for osteosarcoma MG-63 cell apoptosis and related apoptosis protein expression, we found that the luteolin induced cell apoptosis mechanisms may involve with down-regulation of BCL-2 protein, up-regulation of BAX protein expression, increased BAX/BCL-2 ratio, and the activation of Caspase 3 protein cascade reaction. The gene discussed is CASP3; the disease is osteosarcoma.