The article examines three competitive hypothesis in regard to the assumption that; in changing international security, the actors, armaments and new sources of threat are effective to international security, therefore, to measure the effects of these variables would ease our understanding of such a development on the concept of international security at the time of globalization.The first hypothesis states that, multinational companies, international institutions and organizations, and also individuals are among new actors in global scene.The second hypothesis explains that, whereas the traditional threats to international security were mainly to use force and resort to conventional military means, but today, the dimensions of these threats have changed into non-military actions, including political, social, economic and ecological, such as terrorist attacks, virtual terrorism (digital attacks).The third hypothesis indicates that, the expansion of massacre weapons, including nuclear, biological and chemical, not only have not increased the security of states and international system, but in reality, have made more serious threats to international security.To review the data based on the aboved three hypothesis, indicates that, instead of diversity and plurality of actors, expansion of massacre weapons and arising of new recourses of threats to international security, war as a political instrument in relations between states has been abolished.Increasing economic benefit of peace and mutual dependencies among states have replaced the move towards democratic peace as a security strategy. As a result, security studies on the basis of traditional approach has lost its importance and new security studies are followed on the basis of Copenhagen School which studies security in the framework of economic security, ecologic security, social security and human development, rather than, military security.