This paper attempts to analyze the conditions to be met in the case of armed intervention for humanitarian purpose. Under the current regime of international law, a most controversial issue of international law today is that if and when without UN Security Council authorization or General Assembly action, any use of armed force for humanitarian intervention would be regarded as lawful or not. Because of inaction from Security Council owing to veto power wielded by Permanent Member states or no endorsement from General Assembly due to lack of consensus among member states, there arises a legal impasse of being no action for supporting a proposed case of humanitarian intervention, overlooking the human rights catastrophe. With these cases the overwhelming majority of contemporary legal opinion has been addressed against the existence of a right of humanitarian intervention. The rationale to defend conservatively the current collective security framework of the UN Charter is that at most the doctrine of humanitarian intervention has a tenuous basis, not yet crystallized, in current international customary law. On the other hand, still a substantial body of opinion and of practice has supported the view that when a state commits cruelties against and persecution of its nationals in such a way as to deny their fundamental human rights and to shock the conscience of mankind, intervention in the interest of humanity is legally permissible. My position in this paper is to take an affirmative approach to the issue based on customary rule of international law. Although careful analysis is needed for armed intervention to pass the current criteria of legality under international law system, a genuine case of humanitarian intervention should not be frustrated which might be caused by malfunctioning of UN driven not by interest of peoples but by interest of super power countries. Conditions to pass for humanitarian intervention by intervening states would be as follows: first, when faced with an overwhelming humanitarian catastrophe, which a government has shown it is unwilling or unable to prevent or is actively promoting, the international community should intervene. Because Intervention in internal affairs of other country is a sensitive issue, so there must be convincing evidence of extreme humanitarian distress on a large scale, requiring urgent relief. it must be objectively clear that there is no practical alternative to the use of force to save lives; secondly, any use of force should be proportionate to achieving the humanitarian purpose and carried out in accordance with international law; thirdly, any use of force should be collective. No individual state can reserve to itself the right to act on behalf of the international community. Furthermore in some extreme cases such as genocide or crime against humanity, a right of humanitarian intervention may be turn into a duty to intervene where the doctrine of responsibility to protect would be employed. At present this doctrine of responsibility to protect may be better justified in terms of enhancing the legitimacy of international law system rather than by merely satisfying the legality of its action under current system of international law. In this regard I would take an affirmative view on the possibility of humanitarian intervention in an extreme case of human rights catastrophe. With this view I would take also an affirmative stance in the case of probable North Korean crisis of human rights catastrophe with a similar magnitude and gravity. If the escalating worst scenario of the chaos and humanitarian catastrophe in North Korea would bring forth an international intervention to stabilize the situation in North Korea. then such an event requires aforementioned conditions to be met for permitting humanitarian intervention.