English has been a lingua franca in various domains of communication such as international business, academic conferences, diplomacy, science and technology. As a result, the demands for English skills in all aspects are crucial in response to the importance of English and the impact of globalization. Despite the constant efforts in developing English education in Thailand, a number of studies have shown that the achievement of Thai learners was unsatisfactory. Given the role of English as an international language which is used in almost domain of communication, amongst several factors hindering the success of English language learning, English pronunciation of the Thai learners should be focused.