Abstract – The aim of this study is to identify similarities and differences among phonological system of Russian, English and Persian languages. To achieve this, the main differences and rules on phonological system of these languages have been gathered. The data is presented in a systematic order. Moreover the study tries to identify the problematic areas in production of these sounds. The model used is Yarmohammadi's (1996). In this model, there are basically two choices for phonological comparison: taxonomic phonology and generative phonology. In this study the taxonomic model has been adopted because it is more suitable “for phonological CA, particularly in applied areas”. The results indicate that when a syllabus structure does not exist in a language it makes problem for correct pronunciation, and language learners try to use approximate syllables in their mother tongue and the issue is salient in Persian-speakers; however, the deviation in the vowels' behavior can be a very prominent linguistic phenomenon. This study can express a path for further studies on other linguistics field such as morphology and syntax. Keywords: Comparative, Typology, Phonology, Linguistic

Keywords