Polymer and its composites have replaced a great number of metal products in industry and are still in a rapid growth in many areas due to their attractive properties such as low density, high specific strength and specific stiffness, corrosion resistance, and manufacturability. The properties of polymers have been considerably improved by the incorporation of fillers and fiber reinforcement. The mechanical and tribological studies on polyphenylene sulfide (PPS) and its composites have not been hitherto carried out extensively and are deserving of attention in view of their potential for being used in a wide variety of applications.;PPS has a great potential in high speed sliding applications owing to its high temperature capability. However, its wide application as a promising matrix material in tribology is still at infancy and so there is a need of the comprehensive study of its mechanical and tribological behaviors. In this dissertation, the effect of fillers and fibers as reinforcements in PPS was performed with respect to the tribological and mechanical properties. A number of fillers based on the minerals abundantly available in Armenia were used in this study along with other inorganic compound fillers and short micro fibers as reinforcement. The fillers used were both in micro and nano sizes. Finally, the effect of carbon nanotubes and carbon nanofibers as the reinforcements in PPS has also been studied in terms of their thermal, mechanical and tribological properties.