The high school system in Korea has undergone significant transformation in the Lee M-B
conservative government's diversification policy, which embodies aspects of the classed competition
system. The purpose of this article is to analyze the social characteristics and limits of the ‘Korean
High School Diversification 300 Project(High School Diversification Policy)’ carried out by the Lee
M-B government. In particular, this article focuses on the horizontal stratification of high school as a
class practice of the middle class which tries to obtain academic capital with high status value useful
for entrance into top universities. The high school diversification policy was introduced by a
neo-liberal regulatory government to support the establishment of a new development framework for
national advancement(先進化). The purpose of the diversification policy is to change the high school
system from an equalization system based on egalitarianism and universalism to a de-comprehensive
system based on efficiency and possessive individualism. As a result, high school system is
functionally differentiated as well as horizontally stratified by student’s class and ability. Because
horizontal stratification of school reflects social stratification, the lower class and less achievement
students are socially stigmatized and self-excluded. In the university entrance system, the
diversification policy has the unintended role of strengthening the university rank system.