The development of polymers is the biggest achievements made in chemistry which has a significant effect on everyday life. Remarkable improvement in humanity’s progress has been observed from the “Stone era” to the “Iron era” to the “Bronze era” to the “Polymer era”. Polyimide is a polymer of imide monomer. Polymerization by Diels–Alder reaction is one of the promising trends in the preparation of polyimides. Furan ring is one of the most thoroughly studied diene which display a pronounced dienic character, makes it highly suitable as diene. The use of bismaleimide as dienophile is very useful because double bond of maleimide is quite reactive towards electron rich diene, to give a normal demand Diels–Alder cycloaddition. Owing to the published work on these topics and long-standing interest of my laboratory in the study of polyimides via Diels–Alder reaction, a synthetic work on novel polyimides have been carried out. Aim of this book is to provide a brief knowledge about polyimides which were synthesized from bisfuran and various bismaleimides.