Conducts pure shear and axial tension/ pure shear experiments on rectangular rubber specimens under different displacement load levels, and investigates Mullins softening induced anisotropy of rubber materials under tension/ shear load. The experimental results show that because of the effect of Mullins softening induced anisotropy, the pure shear test on the specimens after axially tensions causes the specimen lateral stiffness increasing. Uses the axial tension/ pure shear experiment data of rubber specimens to fit and obtain the relevant Mullins softening control parameters, and reflects the effect of Mullins softening induced anisotropy on the transverse stiffness. Makes finite element simulation on the transverse stiffness curves of the specimens under two kinds of load tests, and compares the mean sum of squared residuals between the simulation estimate value and the experimental value. It is considered that Mullins softening induced anisotropy will significantly increase the prediction accuracy of transverse shear stiffness of rubber elements under tension and shear load.