Abstract First-principles calculations based on the density-functional theory were employed to investigate the electronic structure and cohesive properties of Ti–Sn alloys. Based on the calculated results, the lattice constants, bulk modulus and formation energies for the Ti–Sn intermetallics were compared with previous experimental and theoretical investigations. It was demonstrated that in term of the means volume and cohesive properties, the structure stability of Ti–Sn intermetallics increased with decreasing Ti composition, which was also supported by the analysis of densities of states. Furthermore, it was found that the difference in stability between the Ti–Sn intermetallics could be attributed to the bonding electron numbers at the upper region of the valence-band complex, which was cut by Fermi level. In addition, the electronic structure of the Ti–Sn intermetallics also showed a strong hybridization between Ti 3d and Sn 5p states, which played a dominant role in the bonding mechanism of Ti 3Sn and Ti 2Sn.