Poly(2-ethyl-2-oxazoline) (PEOx) was blended with the lithium or zinc salt of poly(styrenesulfonic acid) (PSSLi and PSSZn, respectively). Each PEOx/PSSLi blend showed the existence of two glass transition temperatures (T(g)s). The lower T-g value is close to that of PEOx. The upper T-g value is substantially lower than that of PSSLi, indicating that the two polymers do interact to a certain extent. The T(g)s of PSSZn and some PEOx/PSSZn blends could not be detected. A single T-g was observed for PEOx/PSSZn blends containing 0.20 and 0.40 mole fraction of PSSZn, and the value is substantially higher than that of PEOx. PEOx/PSSZn blends are considered to be miscible. Fourier transform infrared spectroscopic measurements showed that both PSSLi and PSSZn interact with amide carbonyl oxygen atoms of PEOx. X-ray photoelectron spectroscopic studies showed the development of high-binding energy (BE) N1s peaks in all the PEOx/PSSZn blends but not in the PEOx/PSSLi blends. The interaction between Zn2+ and the carbonyl oxygen atom is so strong that there is an electron migration from the nitrogen atom to Zn2+ via the carbonyl group. Interaction between PEOx and PSSLi or PSSZn is also evidenced by the development of a low-BE S2p doublet in the blends. However, the Li1s and Zn2p peaks did not show significant changes upon blending the polyelectrolytes with PEOx.