Thermoplastic polymer blends composites were prepared as strips by double screw extruder. The prepared composites consists of two groups, the first group was prepared as ternary polymer blend according to the formula [84%LLDPE:15%((100-X)%PP:X%PVP):1%B.P] with X values (0,4,8,12,16%).The second group was prepared with replacing the weight ratios for each of the LLDPE and PP according to formula [84%PP:15%((100-X)%LLDPE:X%PVP):1%B.P] with same X values. Mechanical properties for all prepared samples (tensile, flexural, compression, impact toughness, hardness and creep tests) were studied. The results of this research showed that the fracture strength, young modulus, compressive strength, flexural modulus and creep modulus for the two groups increase with increasing in PVP percentage and the highest values were at 8%PVP, while elongation decreases with addition PVP to the composites. Moreover flexural strength, shear stress and hardness values increase slightly with increasing in PVP percentage for both groups. In addition to that, the impact strength and fracture toughness for the second group samples were high and reach the maximum values (0.45 kJ/m²) at 4%PVP and (4.58 Pa√m) at 8%PVP respectively, as well as all results show that the second groups samples have better mechanical properties.