Vascular endothelial growth factor (VEGF) is a homodimeric heparin-binding protein (34-42 kDa), which induces formation of new blood vessels (angiogenesis). VEGF-mediated capillary invasion is an essential signal that regulates growth plate morphogenesis and triggers cartilage remodeling. Thus, VEGF is essential coordinator of chondrocyte death, chondroclast function, extracellular matrix remodeling, angiogenesis and bone formation in the growth plate. VEGF expression in untreated osteosarcoma is predictive for pulmonary metastasis and poor prognosis. VEGF concentration in the serum of patients with malignant bone tumors (osteosarcoma, Ewing's tumor) increased in comparison with norm and benign tumors. VEGF expression in the serum of patients with osteosarcoma associated with the development of metastasis and without metastasis period. The results of investigation indicate the existence of dependence between VEGF expression and degree of tumor malignancy and metastasis. These results testify probable participation of VEGF in biology of the tumor-transformed tissue.