本篇論文嘗試以非派生和派生兩種不同結構基礎的優選理論來分析臺灣閩南語仔前變調以及暱稱仔詞綴變調。非派生的優選理論認為聲調改變僅需一個步驟就可以完成。仔前和暱稱仔詞綴音節本身都有兩種讀法，不同的變異體可透過共同音韻模型 (Cophonological model) 下的次文法，也就是制約的重新排序來解釋。本篇研究認為調素傳替與否是仔前音節不同聲調的來源，透過 SHARE (t) 和 NOLONG (t) 兩種制約的排序，可以預測調素是否傳替。另外，透過 SHARE，NOLONG 和 TONAL MARKEDNESS 三種制約的互動和階層性的排序，可以預測暱稱仔詞綴的變調兩讀。派生優選理論則認為仔前和暱稱仔詞綴的聲調變化是一種階段性，而且是一種趨向最佳化的改變，亦即每一個步驟的輸出值都比上一個步驟的還來的優質，為仔前和暱稱仔詞綴變調提供另一個理論詮釋的觀點。在派生優選理論的框架下，仔前變調需要三個步驟，亦即一般變調、調域傳替以及調素傳替的有無。暱稱仔詞綴變調也是需要三個步驟，第一是沒有聲調徵性的聲調加插；第二是調域傳替或是低調域加插；第三是調素傳替或是低聲調徵性的加插。同樣的， 透過 SHARE (t) 和 NOLONG (t) 的排序，可以預測仔前音節的不同聲調。透過 SHARE，NOLONG，TONAL MARKEDNESS 和 REGISTER MARKEDNESS 的排序， 可以預測暱稱仔詞綴的不同聲調。 / This thesis attempts to analyze the pre-a1 tone change and hypocoristic -a2 suffix tone change in Taiwan Southern Min from the perspective of Optimality Theory and Harmonic Serialism, a derivational version of Classic OT. Classic OT, which implements parallelism, explicates the tone change phenomenon in one-step fashion. The two tonal variants of the pre-a1 and -a2 syllables can be accounted for through the constraint re-ranking in Cophonology Theory. The interaction between SHARE (t) and NOLONG (t) determines whether the terminal toneme will perform spreading in the pre-a1 tone change. In the -a2 suffix tone change, the interaction amongst SHARE, NOLONG and TONAL MARKEDNESS determines whether -a2 will receive a tone spread from the neighboring TBU or associate with a default L. Harmonic Serialism, which assumes harmonic improvement over the course of serial derivation, provides an alternative treatment for the pre-a1 tone change and -a2 suffix tone change. In Harmonic Serialism, the pre-a1 tonal alternation proceeds with three steps, viz. regular tone sandhi, register spreading and terminal toneme spreading. -a2 suffix tone change also requires three steps in terms of Harmonic Serialism, that is, featureless tone insertion in the first step; register spreading or low register insertion in the second step; and toneme spreading or low tonal feature insertion in the final step. Likewise, the ranking conditions between SHARE (t) and NOLONG (t) predict whether toneme will spread in the pre-a1 tone change. In the -a2 suffix tone change, the alternative rankings among SHARE, NOLONG, TONAL MARKEDNESS and REGISTER MARKEDNESS decide the application of tone spreading or default L insertion.