This book examines the genetic resources and crop breeding of Jatropha species, and their uses for biofuel production in Brazil. This book intends to draw attention to a number of species which should contribute with the improvement of plant breeding in Jatropha. It is hoped that the information compiled will contribute to: (a) identifying possible untapped genetic diversity for breeding and crop improvement programs and (b) detecting existing gaps in available conservation and use approaches. In addition, it is hoped that the book will form a valuable reference source for all those scientists involved in conservation, research, improvement and promotion of the Jatropha crops. The book has six parts and a glossary: in the first part is discussed the Caatinga biome, the second part is presented the Jatropha Genus, focusing on three species: J.curcas, J.ribifolia and J.mollissima. The importance of biodiesel in Brazil is contrasted in the third part. The fourth part describes the genetic resources. With the higher priority, the fifth part examines the crop breeding and the final section outlines the recently researches with Jatropha species in Bahia State of Brazil.