Ten types of cationic glycidyl triazole polymers (GTPs) are prepared from combinations of five alkylimidazolium units (methyl-, ethyl-, n-propyl-, iso-propyl-, and n-butyl-imidazoliums) and two spacers [di-and tri(ethylene glycol)s]. Since these poly(ionic liquid)s are prepared from the same sample of glycidyl azide polymer by postfunctionalization method, they have the same degree of polymerization. Therefore, the structure-property relationship can be discussed without influence of molecular weight difference. The samples are characterized by NMR, differential scanning calorimetry, and thermogravimetric analysis. The ionic conductivity data are obtained by impedance measurements. The GTPs with the tri(-ethylene glycol) spacer and ethyl-and n-butyl-imidazolium units afford the highest anhydrous conductivity of 1.5 3 10 25 S cm 21 at 30 8C. Based on electrode polarization (EP) analysis, we calculate the conducting ion (carrier) concentration and mobility. We discuss the effect of the spacer and N-alkyl tail structures on the ionic conductivity using the data obtained by EP analysis and X-ray diffraction.