The structural, elastic and electronic properties of compressed ZnP 2 were investigated by first-principles total energy calculations. The optimized equilibrium structural parameters agree well with those of experiments for α-ZnP 2 and β-ZnP 2 at zero pressure. α-ZnP 2 transforms into I4 1 /22 phase (referred as γ-ZnP 2 ) at 11GPa, which is an indirect band-gap (∼0.78eV) semiconductor. Space group of low pressure phase is the subgroup of that of high pressure phase. The calculated elastic constants for α-ZnP 2 and β-ZnP 2 at zero pressure as well as γ-ZnP 2 at phase transition pressure determine their stability mechanically. Phonon calculation confirms dynamical stability of γ-ZnP 2 .