AbstractIn this paper, the special effect of liquid crystal stationary phase is expressed in terms of ΔI, the difference of the retention index of probed solute between mesomorphic phase and isotropic phase. A series of compounds with different structures and polarities are selected as probed solutes for the investigation of their retention behavior on liquid crystal PBOB and MPBOB. According to the differences of ΔIof various solutes, the rule of special selectivity on liquid crystal is explaine