Genomics research has great potential to revolutionize the discipline of plant breeding. Pigeonpea is an important grain legume mainly produced in semi-arid region, where it plays a crucial role in food and nutritional security of the people. It has the potential to be identified as an important food crop under changing climate. Pedigree and molecular diversity analysis in cultivars developed through classical breeding approaches indicated narrow genetic base in pigeonpea. Genetic and genomic improvement of pigeonpea is required to increase the productivity to meet the increasing food demand. Areas covered in this book include, construction and preparation for Expressed Sequence Tags library, sequencing by most traditional as well as next generation platform, assembling sequencing data, gene prediction, development of molecular markers (SSRs) and evaluation of this bio resources in biodiversity, phylogeny analysis across legume species. The book, therefore, should prove useful not only for students and teachers, but also for the young researchers starting their research career in the field of plant genomics.