Multifunctional heterogeneous blends offer great possibilities of tailoring properties of materials. In this work polyoxymethylene (POM) co-polymer is blended with ethylene- octene co-polymers with various alpha-octene contents (EOC38 and EOC17) in a complete volumetric content range to fabricate specific multifunctional materials with tailored stress-strain properties. Elastic properties of POM/EOC38 and POM/EOC17 binary blends are evaluated by considering Voigt, Reuss and Kerner models. It is shown that Kerner approach is more suitable for prediction of the modulus of the investigated blends in comparison to Voigt and Reuss models. It is shown that in both blends POM has a tendency to form continuous phase up to EOC contents of 0.61 and 0.78 vol. p. for POM/EOC38 and POM/EOC17 respectively. The tendency of EOC to form a matrix is not so expressed.