The expression of protein vascular endothelial growth factor (VEGF) in osteosarcoma cells transfected with adeno-associated virus (rAAV)-antisense VEGF was studied to provide the foundation of osteosarcoma treatment through antivascularization. The rAAV-antisense VEGF at different doses (0, 20, 50, 100, 200, 240 microl) was transfected into osteosarcoma MG-63 cell. The cells and culture supernatants were collected before and after tansfection. The expression of VEGF protein was detected by using immunohistochemical staining (SP) and Western blot. SP and Western-blot tests revealed that the MG-63 Cells transfected with rAAV-antisense VEGF had less staining than those without transfection with rAAV-antisense VEGF, and the staining intensity was negatively correlated with the doses of genes. The corresponding A values of transfected genes with different doses of rAAV-antisense VEGF (0, 20, 50, 100, 200, 240 microl) were 86614 +/- 13776, 73245 +/- 15414, 61078 +/- 12124, 54657 +/- 10953, 39802 +/- 11308, 32014 +/- 15057 respectively, with the difference being significant (P<0.05). It was concluded that the expression of VEGF protein in MG-63 cells could be inhibited by rAAV-antisense VEGF.