Introduction: Each geographic region and each country is defined by two factors: 1- Focal point or political center, 2- certain realm and domain.According to international regulations, all countries have certain territorial area which is recognized by International institutions and other countries that is displayed on the world political map. In addition to the official concept of realm, on the basis of Islamic attitude, it is possible to consider another domain for each country which is called sphere of influence.Sphere of influence is a geographical domain theta country is able to control its existing environmental process in perceptible or imperceptible form. The sphere of influence of a country is the total of various political, economic, military, geographical and cultural factors. On the basis of this article, the cultural and soft factors and sources are considered as the most principal factors affecting countries' sphere of influence.With respect to the this point, the present article emphasizes the Islamic attitude in the domain of political thought, and therefore, this research tries to study and discuss the role of cultural factor and soft sources of power in expanding sphere of influence of countries using the principals of Islamic-political thoughts.In this relation, there is a question that is: “what is the sphere of influence and what factors does it have? In response to this question, a hypothesis is presented that is: “it seems that sphere of influence consists of a country’s influence that exerts and the major index in specifying this sphere is the index of cultural authority...