Abstract: The structural,elastic and electronic properties of Li3Bi have been investigated by using first-principle pseudopotential method within the framework of density functional theory.The calculated equilibrium structural parameters agree well with the experiment.The enthalpy and elastic constants calculations show that Fm-3m structure is the most stable structure at zero pressure. For Li3Bi, the calculated bulk modulus,shear modulus,and the Young's modulus are 30.2 GPa,25.5 GPa,and 59.6 GPa,respectively.When the Debye temperature is 312 K, Li3Bi has small elastic anisotropy.Li3Bi is an indirect semiconductor with narrow band gap (0.45 eV).