Stress induced anisotropy has important influence on soil’s stress-strain relationship under complex stress state. Traditional constitutive model with isotropic assumption cannot describe this character. Influence of anisotropy on hydraulic fracturing of earth core dams is analyzed herein. A new anisotropic soil constitutive model is applied to the finite element analysis of a high earth core dam. Minor principal stressσ3 got from anisotropic model is larger than that from Duncan E-v model. It is proved that the estimate of the hydraulic fracturing of earth core dams with Duncan E-v model will be more dangerous.