A new type of column packed with polystyrene gels which have a broad pore size distribution in a particle (henceforth referred to as the multipore column) was developed, and its performance was compared with the so-called linear column (henceforth referred to as the mixed-bed column). The chromatogram of the epoxy resin (Epikote 1009) on the multipore column showed a monomodal distribution, but the chromatogram on the mixed-bed column showed the inflection on the chromatogram at the molecular mass of about 10,000 as polystyrene equivalent. There was a big difference in the pore size distributions of gels packed in the two types of columns; the pore size distribution of the multipore column showed the trapezoid, while that of the mixed-bed column had sharp maxima for pores with a diameter of 0.08 μm. This difference in the pore size distribution may be the main reason for the inflection phenomenon, though the calibration curves of these two types of columns were almost the same. The multipore column also had the advantage of the mixed-bed column in the linearity of the calibration curve.