Aromatic PI has already been applied to aeronautics and astronautics due to its comprehensive performances. Most PI is not easy processed for its dissolving and fusing hardly. As a high performance engineering plastic, the GCPITM thermoplastic polyimide has excellent thermal characteristics and can be processed by thermal molding, extrusion and injection methods while still has remarkable heat resistance, mechanical properties, dielectric strength, anti-corrosion, radio-resistance etc. It was proved that the GCPITM composites mechanical properties, self-lubricated property, etc can be improve evidently by compounding with carbon fibres, glass fibres, PTFE, graphite and so on. The GCPITM can be formed into membrane, tube, column, or clubbed products and can be applied to some sophisticated components, such as gear, seal ring, bearing, socket connector, etc. In some special conditions, it is also an ideal material which can replace metal, ceramic, thermosetting resin, thermoplastic plastic with a low use temperature or hard-processing PI.