In this work, a liquid aniline was studied in a pure and aqueous solution using experimental and theoretical calculations. Using Raman spectra, the region of 100–3200 cm−1 was analyzed, and blue shift and red shift were observed in this region. For the first time, the reasons for this shift were found to be due to the C–H···O nonclassical hydrogen bonding in the complex formation and were confirmed in the results calculated using the theoretical DFT//BL3YP/6-311+G(2d,p) method. Mechanisms of aggregate formation with aniline+(H2O)7 molecules were also analyzed using theoretical calculations. Calculations show that the total energy increases with the increase in the number of water molecules in the formation of aggregates.