This study evaluated some physical and mechanical properties of polypropylene (PP) composites reinforced with various mixtures of the cone flour and the wood flour. Five wood plastic composite (WPC) types were made from the mixtures of cone flour/wood flour/PP/coupling agent, respectively. Water resistance and flexural properties of the composites were negatively affected by increasing cone flour content. We concluded that extractives in the cone flour on the mechanical properties of wood-polypropylene (PP) composites had a significant effect on the flexural properties of the composites. Based on the findings obtained from the present study, with the addition of 10% cone flour to WPC, the water resistance and flexural properties did not significantly affected as compared to WPC made from wood flour.