This study reviews how historical factors affect the ownership structure and the corporate governance of Korean Business Groups. From the starting points of the economic development, Korean government has performed as the critical role in forming Korean big business. Despite Korean business groups were already established earlier 1960s, there was no agency problems between controlling shareholders and outside investors, because almost all affiliates of business groups were not listed that time. Pushing forward the policy promoting heavy chemical industries, Korea government enforced the affiliates to be listed on the stock market. This policy incubated the agency problems between stockholders, but the corporate governance has not been seriously concerned in Korean society, because the government worked as the guardian of the controlling shareholders of business groups until the Asian crisis. Korean government drastically lose the controlling power to the financial market right after the Asian crisis, then Korean business groups had to face the crisis in the corporate governance. The stock market influences have been gradually raised so that it improved the corporate governance of Korean business groups. However since the late 2000s, the voices requiring the social responsibility to business groups are growing in Korean society. This trend might become the new latent problem to the corporate governance in Korean business groups, because it could shake and transmute the shareholder maximization incentives by the controlling shareholders.