Abstract
Peridotite xenoliths from Iraya volcano, the Philippines, are known as metasomatite by SiO2-rich aqueous fluids (and melts). The petrographic features are similar to those of Avacha peridotite xenoliths, containing abundant H2O fluid inclusions, and it is expected that the Iraya xenoliths also contain a large amount of H2O inclusions. We would like to discuss about the relationships between the general features of H2O fluid inclusion and petrographical features (presence or absence of metasomatic minerals and their mode of occurrence) of host peridotite xenoliths.