An Introductory Course of English Phonetics and Phonology aims at meeting the needs of EFL learners in Iran and elsewhere to gain knowledge about the fundamental concepts in Phonetics and Phonology and to improve their pronunciation of English. Attempts have been made to describe the difficult topics in this field in clear and simple English; however, where the use of technical terms has been unavoidable definitions have been provided in the glosses to help students follow the discussions. Furthermore, figures and illustrations have been used to make the description of sounds easier.