With the implementation of the Joint Comprehensive Plan of Action（JCPOA）on the Iran nuclear issue on January 16th 2016，the EU and the US' announcement of partial lifting of sanctions on Iran，Iran's role in the international political and economic arena would be enhanced.Iran has resumed normal political and economic relations with the EU member countries.The two sides have signed a number of trade cooperation agreements，and the trade volume has increased substantially.But the Iran-US relation has largely restrained Iran's economic and trade cooperation projects with EU member countries，leaving many uncertainties in the actual implementation of the projects.Although achieving temporarily moderation in the Obama Era，Iran-US relation has achieved no substantial breakthrough.After President Trump came into power，relations between the two sides were again strained and uncertain factors increased.The two parties has effectively controlled the military friction in the Persian Gulf and achieved the“exchange of prisoners ”.The United States has paid arrears of Iran and allowed Iran to buy airbus and Boeing aircraft.The bilateral economic and trade amounts has also increased.Besides，the US has admitted that Iran has not violated JCPOA.In spite of all these，Iran is still listed as a“terrorist supporting country”and is condemned as the“culprit”of the Middle East chaos by the US.Using Iran's development of ballistic missiles as a pretext，the US still retained partial sanctions against Iran and added new sanctions and extended the already-expired Iran Sanctions Act，which has aroused strong dissatisfaction from the Iran side.However，the strategic alliance between Iran and Russia has been further deepened.Their bilateral cooperation in international affairs，regional security and economic and trade relations has been further intensified.Economic and trade volume has also increased considerably.