TiO₂-based dye-sensitized solar cells (DSSCs) have been widely recognized as one of the most promising photovoltaic cells because of their interesting construction and operational principles, decorative natures, and low-cost production. To develop high-performance DSSCs, an epoch-making molecular design toward creating efficient dye sensitizers is required. For this purpose, we have designed and synthesized a new-type of D-π-A dye sensitizers with azine ring such as pyridine, pyrazine, triazine and pyridinium ring, as electron-withdrawing anchoring group. Our work revealed that D-π-A dye sensitizers with azine rings can adsorb onto TiO₂ surface through the formation of hydrogen bonding, azinium ion or coordination bonding at Brønsted acid sites or the Lewis acid site of TiO₂ surface, leading to efficient electron injection from the dye to the conduction band of TiO₂ electrode. Consequently, we propose that the azine ring capable of binding with both Brønsted acid sites and the Lewis acid site of TiO₂ surface is one of the most promising of dye sensitizers for DSSCs.