This book presents the genetics and genomics of Jatropha, which is used for biofuel, and shows how plant genomics can be used to improve plant breeding. The utilization of plant biofuels is a promising solution to global issues such as the depletion of fossil fuels and resources and climate change. Jatropha curcas L. (jatropha) is a species of shrub belonging to the Euphorbiaceae family. Native to Mesoamerica, it is now grown widely in tropical and subtropical areas in America, Africa and Asia. The seed oil of Jatropha is a suitable source for biodiesel or bio jet fuel, and since it is not edible and can grow in semi-arid lands unsuitable for the cultivation of food crops, its production does not compete with that of food to inflate its price. The characteristics of this promising biofuel plant, however, have not been fully exploited in terms of breeding, mainly because of the lack of information on its genetics and genomics. The structure of the whole genome of Jatropha is analyzed, providing insights into on the plant’s genetic system and accelerating the molecular breeding process.