A new [2]pseudorotaxane from the 1,2-bis(isoquinolinium)ethane axle and the dibenzo-24-crown-8 ether wheel and its self-assembly were investigated by 1H NMR spectroscopy and single crystal X-ray diffraction technique. The results demonstrated that the supramolecular adduct was held together by three noncovalent interaction such as N+...O ion-dipole interactions, C-H...O hydrogen bonding, and -stacking between electron-poor isoquinolinium rings of the axle and electron-rich catechol rings of the wheel. They, furthermore, showed that the phenyl ring as a substituent or a fused ring on pyridinium has a similar effect on the association ability.