A new proton-conducting polymer based on sulfonated hydrogenated polystyrene-butadiene) star block copolymer (HPBSE-SH) has been synthesized and characterized. The free acid samples and their blends with the non-sulfonated polymer (HPBSE) and Polypropylene (PP) were studied. The effect of sulfonation on polymer structure was studied using MR. Dynamic mechanical analysis and differential scanning calorimetry have been used for microstructure characterization. Glass transition temperatures of polystyrene (PS) measured through DMA present an increase about 45 degreesC after sulfonation and an augmentation (10-20 degreesC) as the PP content in HPBSE-SH/PP blends increases. Non-isothermal crystallization of PP was studied using Avrami analysis. Complex impedance measurements have shown that proton conductivity of HPBSE-SH was about 10(-2) S cm(-1) after hydration, lower values were observed generally in the case of blends.