The negative transfer of native language influences the English acquisition process of the college students from Yantai in a great degree,both in the segmental and suprasegmental level,while the consonants in the segmental level are influenced most.The paper makes an experimental phonetic contrastive study on [d?],[t?],[?] in the aspect of frication between native English speakers from America and English learners from Yantai basing on processing a large number of English word corpora by using PRAAT.It is found that the degree of frication of [d?],[t?],[?] in American English is strong,while Yantai weak.
