Abstract Polymer mixing is presently one of the most effective and the most intensely developing methods of physical properties modification for polymers. Mixing polymers one can modify certain properties, mainly physical. In this work, investigation results for mixtures of polyamide 6 with polypropylene have been presented. Mixtures with content of 30, 50 and 70% of polyamide in relation to the polypropylene with compatibilization agent (Polibond 3150) in quantity of 2% have been produced. Ingredients of the mixtures are thermoplastic materials, which belong to the group of constructional materials, but with different properties. Polyamide 6 is characterised by quite good mechanical properties. On the other hand, polypropylene is characterised by poorer mechanical properties as compared with polyamide. Combination of favourable properties of both plastics leads to manufacturing of new plastic mixture nature but with favourable mechanical and application properties. The results of the investigation on PA/PP mixture properties by means of DMTA method shown that increase in PA concentration in mixture has not caused any crucial changes in pattern of dependencies of mechanical loss angle tangent complex modulus E * . Along with the increase in PA amount in PA/PP concentration, conservative modulus value (responsible for gathering and transmitting energy during consecutive deformation cycles) increases, while modulus connected with energy dissipation (in the form of heat) value drops. Having reduced curves for Young's and Kirchoff's modulus ( E ′, E ′′, G ′, G ) on the basis of DMTA analysis a course of Young's and Kirchoff's modulus changes with time calculation in this work have been suggested.