The　geometries,　electronic　structures　and　absorption　spectra　of　the　two　organic　triphenylamine-based　dyes　TA-St-CA　and　TA-DM-CA,　containing　identical　electron　donors　and　acceptors　but　the　different　conjugated　bridges,　were　studied　by　density　functional　theory　(DFT)　at　the　B3LYP　and　PBE1PBE　levels,　respectively.　The　influence　of　para-orientating　methoxyl　units　on　the　electronic　structures　and　light　absorption　properties　of　the　dyes　and　the　consequent　photovoltaic　performance　of　the　dye-sensitized　solar　cells　(DSSCs)　were　investigated　in　detail.　The　results　indicate　that　the　introduction　of　the　para-orientating　methoxyl　units　into　the　conjugated　bridge　induces　the　increased　absorption　wavelength　as　well　as　the　more　negative　E-HOMO　corresponding　to　the　bigger　driving　force　(E-I-(/I3)-　-　E-HOMO)　for　dye　reduction,　which　together　improve　the　photovoltaic　performance　of　TA-DM-CA,　although　there　is　a　decline　of　the　open　circuit　voltage　caused　by　the　more　negative　E-LUMO.