The measured shifts of the retention volume V-R of polystyrene (PS) towards lower values in benzene-methanol (Bz-MeOH), and towards higher values in butanone-heptane (But-Hep) are in agreement with our theoretical model, in which both MeOH and But are adsorbed on Lichrospher. This paved way for us to model the chromatographic stationary (s)-phase as MeOH and the mobile (m)-phase as Bz-MeOH, and to calculate the distribution coefficients for PS. For But-Hep, the s-phase has been modeled as But, and the m-phase as But-Hep. A linear relation for the experimental equilibrium distribution P-sm of PS is shown between the s- and m- phases in Bz-MeOH and But-Hep vs. the logarithm of the molecular mass log M, The s- and m-phases for PS in Bz-MeOH and But-Hep are modeled, and logP(sm) is calculated. The results indicate the preference of PS for Bz-MeOH and But. The calculations predict a V-R shift of PS towards lower values in Bz-MeOH, and towards greater values in But-Hep. The different adsorptions on Lichrospher of MeOH (multilayer) and But (monolayer) affect the magnitude of the V-R shift.