Tospoviruses that have single-stranded, negative sense RNA genomes are members of the Tospovirus genus, the Bunyaviridae family. Tomato spotted wilt virus is the type species of this genus. They are transmitted in a persistent manner by thrips belonging to the genera Ceratothrioides, Dictyothrips, Frankliniella, Scirtothrips, Sericothrips and Thrips and seriously damage vegetables and ornamental crops worldwide. In this report, the current state of knowledge on the biological and genetic structure, transmission mode and classification of tospoviruses are reviewed. The natural occurrence, endemicity and vector insects of tospovirus strains belonging to 29 distinct species including 8 species in Japan are described.