College of Geo- Exploration Science and Technology，Jilin University，Changchun 130026，China

The study on seismic anisotropy is one of the difficult problems in the field of geophysics nowadays． As a method of ray theory， the seismic anisotropy ray tracing is an important means to study the anisotropic seis- mic wave propagation． The traditional ray tracing system formulated in terms of elastic parameters in the anisot- ropy is more complicated than that in the isotropic case． Considering the difficulty，a kind of ray tracing system formulated in terms of phase velocity and group velocity is introduced． The new method is similar to the expres- sions for isotropic media，and avoids the trouble of determining the eigenvalue vector at each time． Besides the ray tracing numerical simulation of different models of vertical transversely isotropic (VTI) medium is carried out，in order to verify the accuracy and applicability of the method and further study the characteristics of wave field propagation in different VTI mediums． The study is certainly valuable in reference for later processing of the anisotropic seismic data．