The fascinating Dirac cone in honeycomb graphene,which underlies many unique electronic properties,has inspired the vast endeavors on pursuing new two-dimensional (2D) Dirac materials.Based on the density functional theory method,a 2D material Zn3 Si2 of honeycomb transition-metal silicide with intrinsic Dirac cones has been predicted.The Zn3 Si2 monolayer is dynamically and thermodynamically stable under ambient conditions.Importantly,the Zn3Si2 monolayer is a room-temperature 2D Dirac material with a spin-orbit coupling energy gap of 1.2 meV,which has an intrinsic Dirac cone arising from the special hexagonal lattice structure.Hole doping leads to the spin polarization of the electron,which results in a Dirac half-metal feature with single-spin Dirac fermion.This novel stable 2D transition-metal-silicon-framework material holds promises for electronic device applications in spintronics.