The viscometric or Mark-Houwink constants K and a for sodium polystyrene sulfonate (NaPSS) standards in two different aqueous solvents (0.1 M CH3COOH/0.2 M NaCl and 0.2 M CH3COOH/0.1 M CH3COONa) were determined at 25.0 degrees C using a Ubbelohde viscometer. They are 3.288 x 10(-3) mL.g(-1) and 1.908 x 10(-3) mL.g(-1) for K and 0.788 and 0.851 for a for the above two solvent systems, respectively. These constants were then used for establishing the universal calibration relationship for a size exclusion chromatography column using the above two aqueous solvents as the mobile phase.