In the midst of 2015, United States decided to lift one of the harshest economic sanctions in the world which imposed to Iran. Previously, for 35 years United States keep sanctioning Iran in many aspects. Since 1979, United States started impose sanctions against Iran caused by the Islamic Iranian Revolution led by Ayatollah Ruhollah Khomeini. Therefore, United States started to impose sanctions against Iran ever since. The various sanctions from United States from embargo, freeze the Iranian assets, stop the import, and ban the Iranian oil. The broke economic condition was expected by United States because of Iranian possession of WMD. However, the Iranian leaders clandestinely build their nuclear capacity increased by the year. Surprisedly, in midst of 2015, President Obama decided to lift the economic sanction to Iran. As the findings, this research proves that there were many influences that affect President Obama in deciding to lift the economic sanction of Iran. United States had choose the most beneficial decision by considering the betterment of international image of United States, the economic situation & military capability of United States and there were internal changing of Iran which were led President Obama decided to lift the economic sanction of Iran.