Abstract:Gaussian beam method is essentially a seismic forward modeling method that combines wave equation and raV theory. Described here are the basic theorV of two-dimensional Gaussian beam arid the waV of synthesizing seismogam. Computation examples of geological models are given. Gaussiari beam method for seismic modeling iri two-dimensional elastic medium can be used to calculate seismic wave fields(including P, SH and converted wave fields) at complicated geological structures in lateral inhomogeneous medium. This method is characterized by no singular area in computation, fast computation and similarity to conventional ray-tracing method. The wave fields calculated by Gaussian beam method represeni cave properties in both kinematics and high-freQuency dynamics. Its computation result is comparable to that of finite difference method.