Fully sulfonated sodium poly(p-styrenesulfonate) (designated as NaPpSS) was prepared from sodium p-styrenesulfonate monomer and the elution characteristics of NaPpSS and commercially available poly(styrenesulfonate) which was prepared by direct sulfonation of polystyrene (designated as NaPSS) were compared using columns packed with glycerylpropyl group-bonded silica gel and poly(styrene sulfonate) gel by changing ionic strengths of the mobile phase. Plots of log [η]M and retention volumes for NaPpSS, NaPSS and pullulan showed that the retention volumes of NaPpSS and NaPSS increased with increasing the ionic strength of the mobile phase, but the extent of changing retention volume was different between these two types of compounds. Early elution of NaPpSS and NaPSS relative to pullulan of the same molecular size is governed by the ion-exclusion effect and NaPpSS eluted earlier than NaPSS of the same molecular size.