Two carbazole-based dye molecules: 3-(6-benzothiazol-2-yl-9H-hexylcarbazole-3-yl)-2-cyano-acylic acid (D3) and 3-[5-(6-benzothiazol-2-yl-9H-hexylcarbazole-3-yl)-thiophen-2-yl]-2-cyan-acylic acid (D4) were synthesized by an approach from carbazole derivate using Vilsmeier-Haack, Suzuki cross-coupling and Knoevenagel reactions. Their physical and electrochemical properties were investigated. D3 and D4 exhibit different optical properties, such as UV absorption, photoluminescence, fluorescence quantum yield and fluorescence lifetime in different solvents. Compared with D3 without a thiophene unit, the maximum absorption wavelength of D4 red-shift obviously and its fluorescence intensity is also enhanced. A shift of the E HOMO and E LUMO is observed for D3 (E HOMO =2.06V, E LUMO =−1.39V vs. NHE) and D4 (E HOMO =1.73V, E LUMO =−1.33V vs. NHE). D3 and D4 can be used as dyes for dye-sensitized solar cells (DSSCs) with TiO 2 nanomaterial because their E HOMO are lower than the conduction band edge of TiO 2 [−0.5V (vs. NHE)] and their E LUMO are higher than the I 3− /I − redox potential [0.42V (vs. NHE)].