Transport properties of sonic wave in a rock are key parameters in reservoir evaluation.Generally,the properties will change with frequency for different rock types,which is very difficult for being measured in a laboratory due to limits of currently experimental technology.In this research,digital core samples were constructed by both the numerical method and the X-ray micron-CT scanning.On the basis of them,dependence of the properties on frequency has been investigated by the Lattice Boltzmann method(LBM)to reveal the relationship between velocity and frequency under different condition.Numerical results show that an obvious change of sonic velocity could be observed in each of the samples.Therefore,a new model has been developed to formulate the relationship in a width range of frequency,which could be used to match up the velocity in geophysical exploration methods.