During the Goryeo dynasty, each estate and stratum was established at different times, and the criteria of the classification and aspects of the existence were diverse. Therefore the study by pluralistic view is needed in order to review the stratification system of that period. In the late Unified Silla, the Golpum (Bone Rank) System was dismantled while the social division and peasantry differentiation were expanded and the local powers came into existence. The social stratification system which had been established through the social changes reflected the expanded social division and incorporated many groups that compete each other. Thus it showed the pluralistic aspects. Yangin(the good-born people)/Cheonin(the low-born people), Sa(the literati)/Seo(the Commoners), Munsin(the civil officials)/Musin(the military officials)/the middle stratum, the scholars/the farmers/the artisans/the merchants, the common people/Japcheok(the ordained village people) and etc were classified and divided in accordance with different criteria. The different criteria inclusive of consanguinity and regionalism, job and obligation, state strength and local autonomy and etc were interacted inside of the Yang estate. Social identity of each estate and stratum was forced by the laws. The laws stipulated the succession of jobs and obligations in accordance with consanguinity and regionalism, and discrimination on the officiation in the government services and the promotion of the official ranks and etc. And the stratification system was closely related to the Bonkwan system. People were locked hierarchically by the system, but meanwhile the people were still competitive and dynamic. From the 12th century, social mobility increased and protests against discriminations uprised frequently.