<p>Polymeric materials and their composites have been widely utilized in previously unimagined areas due to their light weight high flexibility and excellent processing ability. Along with the fast increase in the consumption of polymeric materials in recent years the demand for advanced polymer processing technology is ever increasing. Advanced polymer processing including 3D printing electrospinning extrusion injection molding compression molding casting injection molding etc. can convert polymeric materials into various useful products. Obviously the processing conditions properties and structures of polymeric materials and their composites have a close relationship with each other. The aim of this Special Issue is to present a collection of research or review papers that depict the recent progress in the processing and application of polymeric materials and their composites.</p>