Thermoplastics composites of various polyoxymethylenes (POM) and ethylene octene copolymers (EOC) and it systems with zinc oxide (ZnO) nanoparticles, as well as relationships between structure parameters and properties are studied in the present work. The practical significance of the study is to develop POM/EOC composites and POM, POM/EOC matrix nanocomposites with ZnO because these systems, depending on the ratio of the constituents, form a group of thermoplastic materials possessing broad range of properties. From the wide range of the developed compositions it is possible choose desirable material for selected specific area. In the literature part of the thesis detailed description on the possibilities of forming POM compositions with other thermoplastic polymers and inorganic fillers is given. Influence of the components on the structure, stress- strain characteristics, impact resistance and other significant exploitation properties of the investigated systems is discussed. Aim and tasks of the experimental studies are formulated. Information of the used polymer materials and nanostructured ZnO are described in methodological part of the thesis. Methodological part contains detailed description of the used research methods and the determined parameters: morphology studies by scanning electron microscopy, structural changes by differential scanning calorimetry, relaxation behaviour by dynamic mechanical thermal analysis, stress-strain characteristics by tensile, flexural and impact properties determination methods, frictional behaviour by evaluation of coefficient of friction, processability by rotational viscometry, mass transfer characteristics by sorption and permeability analysis, simulation of the effects of external environment by UV induced weathering and by subjecting to the influence of aggressive chemicals. Structural characteristics and their influence to the stress-strain characteristics, impact resistance, coefficient of friction, barrier properties, rheological, thermal and durability properties indices of the investigated binary (POM / EOC) and ternary (POM / EOC / ZnO) polymer systems are particularly described in the experimental part of the work. The work is written in Latvian language, contains 193 pages. The thesis includes 134 figures, 25 tables, 17 equations and a list with 102 references.