Juvenile squids of Loligo chinensis, 10-55mm ML and L. duvauceli, 10-65mm ML, are randomly distributed in the inner and western Gulf of Thailand at depth of 10-50m, much abundandly deeper than 20m in depth, in offshore of Chonburi Province (Sichang Island, Khram Island, Phai Island and south of Chuang Island) and from Hua-Hin of Prachuab Khirikhan Province to Langsuan of Chumphon Province. Besides, juvenile to adult of other 3 species of small-sized squids were found. Loligo n.sp., 15-50mm ML was first found in the Gulf of Thailand, at depth of 24-50m, in offshore of Pratiew (Prachuab Khirikhan Province) to Langsuan (Chumphon Province). Loliolus sumatrensis, 5-55mm ML, occured at 10-50m depth, abudantly in the inner and western Gulf of Thailand. loliolus affinis, 10-47mm ML, occured in shallower than 20m depth of the inner Gulf of Thailand