Various indicators of corruption show that South Korea has been relatively successful in control of corruption, compared to other Asian countries. Since its independence, South Korea has been transitioning, if not completed a transition, from particularism of the limited access order to ethical universalism of the open access order. How did this happen? This paper first compare the political, economic and social bases of contemporary control of corruption in South Korea with those in the early period of post-independence, focusing on the norms of ethical universalism vs. particularism. Then, the process-tracing analysis finds four periods with different equilibria of norms of particularism and universalism. Each period is defined by major political events such as the establishment of two divided countries (1948), Student Democratic Revolution (1960) followed by the military coup led by Park Chung-hee a year later, democratic transition (1987), and the financial crisis and the first peaceful change of government (1997). This paper also identifies several critical reforms that have contributed to the change of governance norms. The dissolution of the landed aristocracy, relatively equal distribution of wealth and rapid expansion of education due to sweeping land reform (1948 and 1950) laid the structural foundations for the growth of ethical universalism. Gradual expansion of civil service examinations (1950s-1990s), democratization (1960 and 1987), good governance reforms (1988- ) and post-financial crisis economic reform (1998-9) promoted norms of ethical universalism. This paper also explores how these reforms were carried out, who were the main actors, what factors enabled and constrained them, and what impact they made on governance norms.