This studied examined Australian English users and Thai-English bilingual users were competence in recognize word-final stop in English and Thai. A Thai bilinguals lived in Sydney, Australia. In Experimentation 1(discrimination test), For thai bilingual, They were competence to discriminate stop distinction in place of pronunciation in their two languages. But ,English-Talking listeners’ Choosing perform was good only for English. In Experimentation 2 (identification Test) When English stop was generated by native their speaker. While, English listener’s performance degeneration when they heard stop in language not their language. It was appeared to be positive cross-language cause when thai listeners heard Korean. Moreover, Thai bilingual were a similar group with respect to their format of stop knowing. It is advise a strong of the mother languages perception system in adult two languages.