The present study investigated functional group distribution of virgin and aged asphalt binder through liquid chromatography (LC) transform, a device that combines the functions of Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). The corresponding molecular models of virgin and PAV aged asphalt components were constructed. The temperature-dependent density of the model was calculated to verify the accuracy of the model. The chemical structure of the components was evaluated using a series of indicators, including the aromatic index, the aging index, the C=O index and the delta (CH3)/delta (CH3 + CH2). The structural changes of components with molecular weight of the virgin and aged asphalt were also analyzed. The molecular simulation results indicated that the molecular model developed in this study was consistent with real asphalt.