The present invention provides a proton conductive membrane having capabilities of self-generating water and maintaining water, excellent ion conductivity and excellent effect of inhibiting crossover and usable for solid polymer electrolyte type fuel cells and also provides a proton conductive composition used for preparing the proton conductive membrane. The proton conductive composition comprises 100 parts by weight of a polyarylene having a sulfonic group and 0.01 to 80 parts by weight of at least one metal catalyst selected from the group consisting of platinum, gold, palladium, rhodium, iridium and ruthenium, or comprises 100 parts by weight of a polyarylene having a sulfonic group, 0.01 to 80 parts by weight of the metal catalyst, and 0.01 to 50 parts by weight of metal oxide fine particles and/or fibers in total.