This book focuses on a new development of spin giant resonances in nuclei. It covers: quenching phenomena in Gamow-Teller giant resonances, spin-dipole giant resonances, spin-longitudinal and transverse responses in quasi-elastic scattering, microscopic structures, isoscalar spin responses, and spin excitations in exotic nuclei as well as in related fields. The book provides comprehensive coverage of theory and experiment on intriguing spin phenomena, by distinguished contributors.