This paper explores why the development policy and redistribution policy in South Korea has been changed in such a short time during 15years after Asian Financial Crisis, and insists that the party system is the cause for these policy changes, political turmoil. At first, the Kim Dae-jung administration pushed economic reform and restructuring recommended by the International Monetary Fund, partly because it seemed to weaken the social base of the opposition party. Then, under the Roh Moo-hyun and the Lee Myungbak administration, the development and the welfare policy has become the most important issue, but it has been swayed largely in a short period. As the existing major political parties in South Korea doesn't represent the demand of society and bond with its social base through their behavior, the policy orientation of the party and the voters' preference change on every election. The existing party system without representation and accountability causes this politics influx in South Korea.