In this study, effects of natural fiber reinforcement on mechanical properties of polyolefin based hybrid composites widely used different industrial areas were investigated. In this context, jute - PP composites having different jute ratios are produced in twin screw extruder on first stage of production. In the second stage, the films are produced at 450 um thickness of PP material with different jute ratios are placed between HDPE (S 0464) plates with a thickness of 1 mm and are pressed under a pressure of 8.163 bar and temperature of 190 degrees C and consequently hybrid polyolefin composite sheets are obtained. The improvement of mechanical strength of hybrid composite material is realized 8.6 % ratio as 18.41 MPa in 5% jute reinforced hybrid composite. As a result of FTIR characterization, it is observed that the interface agents affecting the mechanical strength positively are significant. When SEM analysis of fracture surfaces formed after tensile test is performed, it is determined that an effective interface is formed between the fiber and the polymer, wheras the fibers that change direction due to production methods adversely affected the mechanical strength.