Today, perfluoro sulfonic acid membranes are the most widely used membranes. However proton conductivity of these membranes is very small at high temperatures and they are very expensive. Therefore studies have been focused on the investigation of alternative membranes. In this study, it is aimed to synthesize an organic-inorganic composite membrane that has better properties than the Nafion (R) membrane. In this study nano sized titanium-dioxide (TiO2) doped phosphonated polyvinyl alcohol (PVA) based membranes were synthesized. Also these membranes were subjected to the characterization experiments such as, determination of water uptake capacity and ion exchange capacity, swelling properties, Fourier Transform Infrared Spectroscopy (FT-IR), fenton tests, mechanical tests and electrochemical impedance analysis (EIS). As a result of all these studies it was determined that the 15% TiO2 doped membrane has the better properties such as highest proton conductivity (0.03 S.cm(-1)), ion exchange capacity (1.04 meq.g(-1)) and water uptake (45%). Regarding the values reported in the literature and depending on the knowledge gained during the fuel cell studies it was concluded that any membrane which has the above properties is suitable for the fuel cell applications.