It was documented that the founders who established Baek-je included On-jo(溫祚), Bi-ryu(佛流), Gu-i(仇台) and Do-mo(都幕). They are not different names of a specific individual who established Baek -je, but are involved in the persons who prepared a base for castle town countries, allied kingdoms and aristocratic government, except Do-mo who was known as a founder of Bu-yeo. On-jo established Baek -je, a castle town country, Gu-i formed Baek-je as an allied kingdom, and Br-ryu was a father of King Geun-cho-go(近肖古) who completed an aristocratic government with centralized authoritarian policy. Do-rno is not directly related to the establishment of Baek-je, but he is assumed to be Dong-myeong, who is a founder of Bu-yeo(夫餘) in respect to conquering royal families of Baek -je. On-jo who came to the South from Jol-bon established Baek-je, a castle town country in the Lirn -jin River area and around the military demarcation line where non -stereobate type Jeok-seok-chong(積石塚) was constructed. King Gu-i was understood as a member of Woo family group, not a direct descendant of On-jo, and when Baek-je reached the stage of an allied country, its sovereign power was held by another family. Bi-ryu who was believed to be an elder brother of Orr-jo was not the person in the same generation as On-jo, but belonged to future generation. Bi-rryu was a father of Bu-yeo, a conquering nation which advanced toward the central area of the Korean peninsular via Ok-jeo(?沮) of the East when it was hit by attack of Mo-yong-ssi(幕容氏) in the late third century. It was more likely that a series of events happening around the sovereign power of Baek-je was settled when a history book was published under the reign of King Geun-cho-go. At this time, Baek-je royal families coming from Bu -yeo pretended that Bi-ryu who is the same person as king Bi-ryu, a father of king Geun-cho-go is a brother of On-jo to emphasize their legitimacy and permanency.