This article successfully analyzed the ranking of constraints for adaptation of sonorant of the English loanwords within the framework of Optimality Theory. Optimality Theory can represent the Standard Chinese phonological structure of loanwords through a series of hierarchically ranked constraints which make them phonologically harmonic with the Standard Chinese. First of all, I designed the ranking of constraints for adaptation of Standard Chinese for this. And I<SUB>DENT</SUB>-IO(rel) that I supposed is also a direct reflection of the principle of faithfulness in that the constraint chooses a right candidate as a optimal output which is realized vowel epenthesis or consonant deletion. After all, I suggest the following hierarchy; C<SUB>ODA</SUB> C<SUB>ONDITION</SUB>, *C<SUB>OMPLEX</SUB>, *σ[ŋ_ ≫ I<SUB>DENT</SUB>-IO(rel) ≫ M<SUB>AX</SUB>-IO ≫D<SUB>EP</SUB>-IO in adaptation of English word-final sonorant in Standard Chinese.