Abstract: The electronic structure and optical and lattice dynamic properties of ZrB2 crystal were calculated with the first principle theory. It was shown that ZrB2 has a metallic characteristic as indicated by the band structure, and the conduction bands are mainly composed of antibonding states of B2p and Zr 4d. On the B plane the σ-bonds are formed by the hybridization of 2 s and 2p orbital, while the pz orbital singly forms a delocalized π bond. These states are directly related to the optical transitions as shown in absorption spectrum. Population analysis clearly showed that a similar charge transfer mechanism from 4d of Zr to 2pz of B occurs in ZrB2 as well as in MgB2. Lattice dynamical results revealed that the vibrational modes which located at B hexagonal plane are made up of high frequency part in phonon spectrum. The prediction of ZrB2 Debye temperature should be 59.14 at 0 K according to the results of phonon.