During recent years the relations between Iran and China has been developing rapidly. Iran has a basically ideological system and China is originally a communist socialist system of governing. No one expects for close political friendship between these two nations. But in the real world we see that these two countries have put aside their differences and a formed a friendly relationship. WHY? What joins these two different nations is their relation with the United States. China and the U.S. do not have a reliable relationship because of their different and some times opposite benefits. Also Iranians have a hostile attitude toward the United States and this has along story. U.S. is trying to prevent Iran from its nuclear activities and calls Iran as the supporter of terrorism. U.S president has repeatedly threatened Iran with international economic sanctions and even military operation. But China not only does not agree any of these choices as the solution for the case but also finds national an economical benefits of China in close peaceful relationship with Iran.