Abstract：Fractures in reservoir must cause the variation of seismic wave characteristic.The variation of wave field characteristic is closely related to the density and azimuths of fractures in reservoir，so that it may be an effective means of ascertaining the fractures. Physical model experiment was done to analyse how variations of fracture density and fracture azimuth influence on seismic wave characteristic.Model experiment says that obvious shear wave splitting may be found when fractunes are dense，and that only slight velocity variation may be observed when fractunes are less dense. Fast shear wave is obviously different from slow shear wave in amplitude and frequency characteristics. The analysis of wave field characteristics is of great significance to fracture prediction.
