Abstract: Abstract In the present study, sarcomas in mice were induced by subcutaneous injections of 3-methylcholanthrene(3-MCA) and the effect of sodium selenite(Se) and vitamin E(VE) on the development of sarcomas were observed.In the mice suplemented with 2. 5 ppm Se in drinking water,the appearnce of sarcomas was delayed and the incidance rate was reduced to 27. 7% in comparision with 53. 5% in the comtrol. However, 1 g of VE per kg of diet did not influence the incidance rate of sarcomas. A combination of Se and VE did not show a increased inhibitory effect on the development of sarcomas than Se used alone.The levels of glutathione peroxidase and Se in bind were significantly elevated by Se supplemention,while no changes occured in the VE grouch. It is well known that Se and VE are antioxidizing agents which may produce cancer preventive effect in some animal modele but,in our experiments,different results were observed in the development of mouse subcutaneous sarcomas induced by 3-MCA.