TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The solid polymer electrolyte membrane includes a sulfonated polyarylene having a constitutional unit expressed by formula (Ia) or (Ib). The sulfonated polyarylene comprises (Ia) (0.5 - 99.999 mol.%), and (Ib) (0.001 - 90 mol.%).Z'=-S-, -O- or -NH-;R=H, F, alkyl (optionally partly or fully halogenated), allyl, aryl, nitro or nitrile;j and k=1 - 4;A' and D'=direct bond, -CO-, -SO2-, -SO-, -CONH-, -COO-, -(CF2)n-, -(CH2)n-, -C(R')2-, cyclohexylidene group, fluorenylidene group, -O- or -S-;R'=aliphatic hydrocarbon group, aromatic hydrocarbon group or halogenated hydrocarbon group;B'=O or S;R1-R16=H, F, alkyl (optionally partly or fully halogenated), allyl, aryl, nitro or nitrile;s and t=0 - 4;andr=0 or more than 1. EXAMPLE - 2,6-Dichlorobenzonitrile (154.8 g), 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane (269 g), potassium carbonate (143.7 g) were added into flask. After being purged with nitrogen, sulfolane (1020 ml) and toluene (510 ml) were added and stirred, and then the reaction liquid was heated to 150degreesC and refluxed. After three hours, when water generation became nearly zero, the toluene was removed. The temperature of the reaction mixture was raised to 200degreesC, stirring was continued for 3 hours, and 2,6-dichlorobenzonitrile (51.6 g) was added, and this was allowed to further react for 5 hours. The reaction liquid was cooled and then diluted by adding toluene (250 ml). After work up hydrophobic unit containing a polymer having a molecular weight 7500 was obtained. A polymer (P1) was synthesized using the hydrophobic unit-containing polymer. The resulting polymer had a molecular weight of 104000. The ion exchange capacity was 2.3 meq/g. A membrane electrode assembly was prepared using the polymer (P1). The mechanical properties of the polymer were tensile strength of 124 MPa; elongation of 40%; and elastic modulus 4.2 Gpa. The polymer had proton conductivity of 0.33 S/cm. The heat test showed unchanged molecular weight and insoluble matter 0%. The power generating performance was 0.656 V and power-generating durability was satisfactory.