In 2003, China surpassed Japan to become the world’s second largest oil consumer (behind the United States), and the third largest oil importer (behind the United States and Japan). China’s huge demand for oil and its dependence on oil imports have forced the Chinese government continuously to adopt the energy expansion strategy in order to secure the country’s oil supply. The energy supply and reserves in Southeast Asian region are not the critical core area to supply China’s energy demand, but it is located in the periphery of China where it controls the transportation link of the Strait of Malacca, directly to hold a strategic point of the sea lane of communication for transporting oil to China. Under this scenario, China is proactively to carry out its energy diplomacy with ASEAN’s nations and to ensure completely an overall strategic arrangement in Southeast Asia so as to assure China’s oil security. In this thesis, it is mainly to probe into the following questions: the inquiring into China’s oil security strategy? Why China and how to readjust its relations with the nations in Southeast Asia? What is the driving factor? After China has become the oil importer, China has to face what kinds of challenges in oil transportation security? What is its intention of resolution projection? In terms of geographic shares, about 60% of the China’s oil import comes from the Middle East, passing through the highly insecure the Strait of Malacca in Southeast Asia that has taken the advantages to influence China’s oil sea transportation routes. Those issues will lay stress on the key points of breaking through the “Malacca Dilemma,” meet the China’s oil demand, sustain economic development, even consolidate the legitimacy of the ruling Chinese Communist Party, and conform to the national interests. / In 2003, China surpassed Japan to become the world’s second largest oil consumer (behind the United States), and the third largest oil importer (behind the United States and Japan). China’s huge demand for oil and its dependence on oil imports have forced the Chinese government continuously to adopt the energy expansion strategy in order to secure the country’s oil supply. The energy supply and reserves in Southeast Asian region are not the critical core area to supply China’s energy demand, but it is located in the periphery of China where it controls the transportation link of the Strait of Malacca, directly to hold a strategic point of the sea lane of communication for transporting oil to China. Under this scenario, China is proactively to carry out its energy diplomacy with ASEAN’s nations and to ensure completely an overall strategic arrangement in Southeast Asia so as to assure China’s oil security. In this thesis, it is mainly to probe into the following questions: the inquiring into China’s oil security strategy? Why China and how to readjust its relations with the nations in Southeast Asia? What is the driving factor? After China has become the oil importer, China has to face what kinds of challenges in oil transportation security? What is its intention of resolution projection? In terms of geographic shares, about 60% of the China’s oil import comes from the Middle East, passing through the highly insecure the Strait of Malacca in Southeast Asia that has taken the advantages to influence China’s oil sea transportation routes. Those issues will lay stress on the key points of breaking through the “Malacca Dilemma,” meet the China’s oil demand, sustain economic development, even consolidate the legitimacy of the ruling Chinese Communist Party, and conform to the national interests.