The central aim of this study is to analyze the effect of peak shifts and intensity changes on the IR and Raman spectrum caused by mono-and di-substituted benzene ring structures. The presence of benzene plays a pivotal role in both biochemical and biological systems. Benzene provides the framework by which amino acids can be analyzed both structurally and functionally to detail the behavior of vibrations on substituted aromatic rings. This analysis will provide detailed information that will further expand the study of aromatic amino acids. Examination of aromatic functional groups in amino acids is essential because benzene is a core constituent of several essential amino acids such as tyrosine, phenylamine, and tryptophan. Analysis is achieved by examining the vibrational modes evident by IR and Raman simulations using the Gaussian software under DFT Restricted, BLY3P 6-31G (d) conditions. The results of mono-substituted IR spectroscopic analysis to date have yielded significant splitting signals at 1650 cm-1 compared to the aromatic ring at the same absorption. The data will be analyzed in terms of its significance to the study of aromatic amino acids.