中文摘要：

通过观察台语同源词中的元音对应关系，可以发现各方言都不同程度地发生过高化、低化或者复化音变，其类型都遵循拉波夫的元音链移通则。台语元音系统的演变规则，可以帮助人们解决台语比较研究中的一些疑难问题。

英文摘要：

While observing the correspondence of vowels in cognates of the TaLlanguage, it is found that the rising, falling and diphthongization of vowels have occurred in varying degree in all dialects, which all follow Labor＇s general principles of chain shift of vowels. The evolutional rules of vowel system may help to solve some difficult problems in the comparative study of the Tai-lan- guage.