In the Northeast and the Northwest Pacific,26 and 68 species of Sebastes Occur, respectively, the similar appearance of some pairs of shallow coastal water species in the two regions having been interpreted as evidence either for migration of ancestral species or of morphological convergence. To distinguish between these competing hypotheses. a portion of the mitochondrial DNA (mtDNA) cytochrome b gene was sequenced from 23 species of Sebastes from the Northwest Pacific and phylogenetic trees constructed so as to include the existing data from Northeastern species of Sebastes. The results clearly indicated separate origins for external morphology in Northeast and Northwest Pacific species. The shallow coastal water species fit the Northwest Pacific are thought to have diverged from about 9.8MYA. Furthermore, the phylogenetic position of Sebastes was inferred among the subfamily Sebastinae, Helicolenus, Hozukius. Sebastes, and Sebasticus, the results suggesting that Helicolenus and Hozukius arc more closely related to Sebastes than Sebastiscus.