When one begins to learn a foreign language, he will find the habits of his native tongue often interfere with his learning the sounds of the new language. Chinese students,especially adults,often find it hard to pronounce some English sounds properly;teachers sometimes also find English sounds can not be casily taught by simply telling a learner what to do with his lips,teeth or tongue etc. Even some English major students find they arc misunderstood because of their incorrect use of a phoneme or an incorrect stress.In a listening test, some students fail to catch the meaning of a certain phrase or a word because they are not familiar with a word juncture or intonation. When a Chinese student learns English pronunciation, he might meet several difficulties.The following are the main factors which may affect his learning, of English.