Foreign policy is a complex of goals, orientations, and instruments that a state adopts vis-à-vis other states in order to achieve its national interests. The aim of foreign policy is to provide security, which covers a spectrum from territorial integrity to the economic development. There are four main factors in foreign policy: understanding the international environment, preparing a strategy for protecting national interests, devising a tactical plan for the implementation of the strategy, and organizing diplomats for the implementation of the tactics. Codifying and implementing of foreign policy depends on internal circumstances, external pressures, perception of statesmen of other states' foreign policy, understanding world events, subjective understanding of peripheral environment by decision-maker agents, and effective diplomacy system. The process of foreign policy's history of Islamic Republic of Iran includes both factors indicating continuity, which is a sign of cohesion of Iran's revolutionary foreign policy; and factors showing discontinuity, which is an indication of approval of evaluating expediency of time per se. With the emphasis on the theme of Iran's Fifth Developmental Plan (2011-2015), approved in January 2010, the author aims to show that Iran's foreign policy is being a changing feature.