The family Pegasidae is found composed of 5 species in two genera, Eurypegasus Bleeker and Pegasus Linnaeus. They contain two (E. draconis (Linnaeus) and E. papilio (Gilbert)) and. three species (P. laternarius Cuvier, P. volitans Linnaeus and P. Lancifer Kaup) , respectively these species are all small, benthic, and covered with plastron from head to tail. Three species have been recorded in Taiwan, but there are many differences between the species names and the specimen illustrations in other foreign publication studies. Recision on the records in Taiwan indicated that three species occur in this region , namely, E. draconis, P. laternarius and P. volitans. According to some osteological and external characters, a hypothesis on the phylogenetic relationship was arrived : P. laternarius is not the sister group of P. volitans and P. lancifer, but the sister group of Eurypegasus species. It is suggested that these five species should be classified in only genus, the Pegasus. Bottom-trawl samplings were made between April 2001 to April 2002 in area of the Kaohsiung coastal at depth around 30 meters. 32 specimens of P. volitans were captured. P. volitans captured its prey by means of oral suction. Guts of the majority of the preserved specimens, including those died right after landed, were empty. Besides some fine granules of sand, one specimen¡¦s gut included caprellideans (Crustacea, Amphoipoda). Skin-shedding was observed numerous times in the aquarium. Unlike other seamoths, only part of the skin was shedded at one time; no regular cycle of skin-sheding was noticed. No social pairing of the sexes and reproductive activity during this study was not noticed. Specimens collected in November tended to be largerin size. The smallest specimens with large ovary was 55mm in length, whereas the largest dry female specimens with a 1.2mm egg was 70mm.. Histological evidence (individual female had eggs in various developmental stages at the same time) indicates that this species is a multiple spawner.