A tin meso-tetra(p-sulphophenyl)porphine sodium salt (SnTPPSNa4) was synthesized and its photochemical properties were characterized by measuring UV-VIS, cyclic voltammograms and fluorescence spectra. The SnTPPSNa4 was applied to a new type of photoinduced oxygen evolution system as a photosensitive oxidant and the best experimental conditions for this research are discussed in this paper. From the results, it is clear that, under the present condiation, SnTPPSNa4 could efficiently oxide water to evolve oxygen when compared to the conventional oxidant- ruthenium complex ([Ru(bpy)3] 2 + ).