The purpose of this dissertation is to provide an explicit formal account of the loanword tone patterns of South Kyungsang (SK) Korean in terms of their phonology and, to a lesser extent, with respect to their phonetics. The most important point of the current dissertation is that the tone patterns of SK loanwords, based on my own 2265 word collection, are predictable from the combination of various factors, most importantly from syllable weight, that is, heavy syllables have High tone. Unlike the loanwords, the SK native tone patterns are unpredictable since the tone patterns are lexically specified. Another important point throughout the dissertation is that SK Korean is a pitch accent system rather than a tone system based on my previous acoustic study. In SK Korean, the accent is on the rightmost high tone that is followed by Low tone. In this dissertation, we observed that SK Korean is not just a pitch accent language but a pitch accent system having both accent and accentless class like other pitch accent languages based on our own analysis of the affixed forms of SK native and loanwords. Two exceptional groups of loanwords discussed, those which have the geminate /l/ and those having epenthetic vowels, can be explained by various means in the SK accent system. The current dissertation contributes to the study of loanwords in Korean but also serves as a basis for further study on the research of prosodic borrowing.