In this paper, we have summarized the overseas strategy of nuclear power plant decommissioning performed in six(6) major countries. For the decommissioning of nuclear power plant, most of countries have three strategies, i.e., immediate dismantling and/or safestorage and/or entombment, respectively. An exclusive agency for the decommissioning has been established in UK, Belgium, Spain, Italy and Hungary. By the way, other countries such as USA, France, Germany, Japan, Canada, etc. have performed the decommissioning under the operator responsibility. In Korea, the decommissioning of Kori #1 is very close. Accordingly, lessons-learned gained from the previous countries experiences needs to be fed back to the Korean first decommissioning project.