The purpose of this paper is to explain stress shift and its following segmental variations when some suffixes are added to the bases. In the past those were analyzed in stress or vowel laxing phenomenon separately, but rather those should be analyzed in one framework compositively. Therefore in this paper I will introduce a new theory, which is known as Harmonic theory, and confirm that it can solve the problems related with stress and vowel laxing simultaneously. The first thing, as a prosodic approach I am going to analyze vowel laxing according to Liberman & Prince (1977), Burzio (1993), and then next to go to the Harmonic theory approach. Within the theory I will analyze the phonological phenomena harmoniously through the important three levels, M-level, W-level, P-level. Therefore this paper is to show that from the comparison between the prosodic analysis and the Harmonic analysis, what is more natural and harmonious analysis is based on the Harmonic approach.