The reform and opening-up of China contributed to rapid economy growth and a significant increase in national power demands. As a consequence of on-going industrialization，China’s energy consumption keeps increasing，forcing China to become more and more dependent on energy imports. This phenomenon gives rise to China’s energy security problem，which revolves around the security of Chinese oil company’s investments abroad，as well as the security of international energy import routes. Both security concerns involve interactions between China and various other nations，making energy security a vital issue for China’s diplomacy. However，the old behavior pattern of China’s diplomatic theories emphasizes the respect of sovereignty and adopts a non-intervention attitude towards the internal affairs of other nations，which，if strictly adhered to，would prohibit China from taking the necessary actions required to protect its own energy interest whenever conflicts or wars break out in regions related to China’s energy security concerns. This article therefore looks into the transition of China’s diplomatic behavior in the Sudan Darfur Humanitarian Crisis and the later civil war in South Sudan. A signal of China’s modification of former behavior pattern can be revealed in these two issues，which implies that China should play a more active and constructive role in protecting its own energy interest.