As China is just making its international strategy in the 21st century，the Pacific island countries must be included into considered for the following four main reasons. Firstly，from the geostrategic perspective，those countries are located in the vast central and southwest part of Pacific Ocean，are the only sea route between China and South America，Antarctica and Australia，New Zealand. In the military position，these islands form parts of the second and third islands chain of defense network by the US and its alliance. In order to maximize its interests in the Pacific region，China should build a blue water naval. Secondly，in the economy sphere，since the Pacific island countries belong to developing countries，the economic relations between China and those countries have huge development space. As the natural extension of New Maritime Silk Road in the 21st century，the Pacific island countries can be treated as a model of South-South cooperation. Thirdly，in politics perspective，there are many Pacific island countries have diplomatic relations with Taiwan，thus pose a major challenge to the Chinese sovereignty. China should struggle in making these countries return to the track of One China Policy. Fourthly，in the cultural perspective，the Pacific island countries belong to the multicultural area. China should take advantage of its public diplomacy，play soft power influence. In short，with the increase of overall strength of China in the future，when China plan its long term international strategy，the significance of Pacific islands should not be ignored.