The present article analyses the changing relation between South Korea’s legislative and executive branches over the past thirty years since democratization. It examines changes in the legislative process, the budget process, oversight of the executive, international agreements and treaties with other states, and the appointment of high-level political personnel. Whereas there were 938 draft bills submitted to the 13th National Assembly, there were a full 17,822 pieces of draft legislation submitted to the 19th National Assembly. This represents a nineteen-fold increase in the number of proposed laws submitted to the National Assembly during its term in office. The number of laws actually passed by the National Assembly (NA) has also risen from 806 during the 13th NA to 8,011, a slower but still massive ten-fold increase. This article examines the legislative process and considers institutional changes that have facilitated this rapid expansion, and also discusses what can be done to further improve institutions. At the same time, the budget of the South Korean government has risen from 18 trillion won in 1988 to 400.7 trillion currently. The article’s discussion of the budget process includes how the role of the National Assembly has changed in its oversight of the budget process, and offers information about the budgeting process year-to-year. Oversight of the executive is offered as well, and includes a year-by-year summary of how oversight and investigative institutions have evolved. The article concludes with a summary of growing legislative power over the ratification of treaties and the vetting of high-level appointees.