In a study of phonetic differences between English and Thai. The results show that sounds and consonants of English and Thailand are different, including pronunciation is different which mainly affects people of Thailand are very pronounced. For example pronunciation fricative is very difficult for students in Thailand. Because they cannot be voiced out well enough. Another problem is the difference in phonemes between English and Thai that Thai students generally confused and caused the wrong pronunciation. Therefore, this research was made aware of the problems in Thai people experiencing now. And they should be improved for the benefit of living and be able to communicate with foreigners to understand.