The electronic structure and magnetic properties of new Fe-based Heusler alloys Fe 2 TiZ (Z=Ga, Ge, As, In, Sn and Sb) have been studied by first-principles calculations. In these alloys, the 24-electron Fe 2 TiGe, Fe 2 TiSn are nonmagnetic semiconductors and other compounds are all ferrimagnetic metals. Fe 2 TiAs and Fe 2 TiSb are predicted to be half-metals with 100% spin polarization. The spin polarization ratio in Fe 2 TiGa and Fe 2 TiIn is also quite high. The calculated total moment for Fe 2 TiAs and Fe 2 TiSb is 1μ B , which is mainly determined by the Fe partial moment. The half-metallicity of Fe 2 TiSb is stable under lattice distortion. The spin polarization of Fe 2 TiSb is found to be 100% for the lattice variation in a range of 5.6–6.1Å, which is attractive in practical applications.