Despite high efficiencies have been achieved, conventional mesoscopic dye-sensitized solar cells using organic solvents based electrolytes that generally have the disadvantages of high vapour pressure against reliable encapsulation, and most importantly, are not environmentally friendly. Electrolytes based on water, a cheap, earth-abundant, non-toxic and non-flammable solvent, therefore, attracted considerable research interests. Water based electrolyte would negatively shift the conduction band of TiO₂ as the water molecules irreversibly change the interfacial properties of the sensitized TiO₂ film. In our work, tungsten doped mesoporous TiO2 nanoparticle aggregates (TNA) possessing high surface area and superior scattering effect, were developed to induce positive shift of the TiO2 conduction band, enhancing the driving force for electron injection and collection efficiencies. The electrochemical impedance spectra indicate a retarded charge recombination and increased electron diffusion length after W-doping. By fine-tuning the W-doping concentration to 0.25 %, aqueous DSCs produced a significant improved open circuit voltage of 712 mV and a short circuit current of 7.05 mA cm-2, leading to an overall increased power conversion efficiency of 3.40 % at 1000 W m-2 simulated irradiation, which is roughly 25 % enhancement compared to that without W-doping photoanode.