Xarifiid copepods are one of the most common endo-parasites of scleractinian corals in the tropical Indo-Pacific. In this study, two rare species of xarifiid copepods, Xarifia jugalis Humes, 1985 and X. quinaria Humes, 1985, were discovered from 500 colonies of Pocillopora damicornis (Linnaeus, 1758). Both of them are not only new to Taiwan but also new to the waters of North Pacific. A full description of these 2 species is provided to show the possible geographical variations of their morphology.