Exciton can be regarded as an elementary excitation of condensed matter which can transport energy without transporting net electric charge. This book presents research in the study of exciton quasiparticles, including exciton polariton dispersion in multinary compounds; exciton relaxation dynamics in colloidal core and core/shell CdSe nanorods; solitons and excitons in seismotectonic problems; exciton diffusion length measured by surface photovoltage method; and excitons in CdO parabolic quantum dots.