The Southeast Asia (SEA) is not only rich in multicultural areas but also rich in multilingual nations with the population of more than 624 million and more than 1,253 languages (ethnologue, 2015). With the cultural diversities of uniqueness of each country, this region also takes their national languages accordance with language planning and political management. This strategy brings the challenges of SEA and it can lead the conflicts among other ethnic groups because of leadership. The ethnic conflicts of SEA are controversial between the government and the minorities such as ethnic conflict in Aceh, Indonesia, Muslim population of the south of Thailand, and Bangsa Moro of Mindanao, the Philippines. The objective of this paper is to investigate the characteristics of the linguistic perspectives of SEA. This research examines the two main problems. First, this paper investigates the linguistic area which refers to a geographical area in which genetically unrelated languages have come to share many linguistic features as result of long mutual influence. The SEA has been called the linguistic area because languages share many features in common such as lexical tone, classifier, serial verbs, verb-final, prepositions, and noun-adjective order and this area consists of five language families such as Austronesian, Mon-Khmer, Sino-Tibetan, Tai-Kadai, and Hmong-Mien. Second, this paper also examines why each nation of SEA take one language to become the national language of the nation. The National language plays an important role in educational system because we found that some nations take the same languages as a national language—Malay language such as Brunei, Indonesia, Malaysia, and Singapore. The research method of this paper is to apply comparative method to find out the linguistic features of the languages of SEA in terms of phonology, morphology, and grammar.