The scope of this work is to investigate the applicability of the evolving factor analysis (EFA) in the characterization of the non-saturated fraction of petroleum mixtures by high performance liquid chromatography coupled with UV diode array detection (HPLC-W-DAD). The EFA was used to interpret the signal obtained from the analysis of fluids, the aromatic peaks of which overlap to a great extent. It is shown that the method can precisely define the elution profile of each one of the constituents and determine the start and the end elution times of the main aromatic hydrocarbon groups based on their differences in the spectrum pattern. In addition, the method gives the UV spectra of the eluting constituents which can be further employed for the compositional characterization of the aromatic part of oil fractions.