In the new century, China's diplomacy would face new opportunities and challenges. China's development became an inevitable trend in the 21st century. The international community's attention was increasingly turning to how China would achieve national rejuvenation and handle its relations with the external world. General secretary Hu Jintao fully expounded the fundamental policies of China's diplomacy in the new era at the 17th National Congress of the Communist Party of China in October 2007. China's diplomacy was based on the Five Principles of Independence and Peaceful Coexistence, which the formulation of "harmonious world" stemmed from and grew upon. The idea of "harmonious world" came up out of inevitability instead of contingency. The "harmonious society" and "harmonious world" was interrelated with each other in a whole thought system. The concept of "harmonious world" made diplomatic thought results more systematic, scientific and practical with more characteristic temper of the age and more profound connotation.