Nanomaterials offer great potential for effective tumor diagnosis and therapy combing diagnostic agents and therapeutic drugs into one platform. In this book, the most recent progress of main nanomaterials and their applications in tumor targeting theranostics is presented. It summarizes the recent advances of current principal nanomaterials in tumor theranostics, including magnetic nanomaterials, quantum dots, mesoporous silica nanoparticles, gold nanomaterials, polymeric nanosystem, carbon nanomaterials, lipopolyplex nanoparticles, microbubbles, upconversion nanomaterials and dendrimers. It will enable readers to get a more realistic understanding of both the advantages and limitations of nanomaterials for potential tumor targeting theranosis. The publication of this book will accelerate the spread of ideas that are currently trickling through the scientific literature. Also a greater understanding of the potential and challenge of nanomaterials for tumor targeting theranostics is highly anticipated for practical clinical use.