Despite a similar amount of proton-conducting moiety, the longer the block length was, the higher proton conductivity was achieved owing to more phase separation between sulfonated and non-sulfonated segments and subsequent well-defined continuous microstructure. No considerable effects of casting conditions on the microstructure and properties of the random copolymer were observed, whereas noticeable variations of the multi-block copolymers were induced; for example, the proton conductivity and water uptake of the multi-block copolymer films cast with a selective solvent (dimethylacetamide) were substantially higher than those of the equivalent films cast with a non-selective solvent (N-methylpyrrolidone). It was also observed that the multi-block copolymer with longer sequence length (15k) was more sensitive to the casting conditions. Our preliminary study also showed that the final morphology and properties also depended on substrate type, rate of solvent removal, and so on. Further investigation will be carried out in order to clarify the interrelationship among casting conditions, microstructures and properties. Also, this study will be extended to the development of measurement scheme of rheological properties (G' and G'') of copolymers in solution-cast films during drying process for the study of transformation and kinetics of the copolymers in solution-cast films.