Abstract: Cement improved loess is often used as roadbed filler in road construction projects in loess areas.Under the climatic conditions of large temperature difference in northwest China, the freeze-thaw cycle will have a significant influence on the stability of roadbed.A series of triaxial shear tests are carried out under different freezing temperatures, times of freeze-thaw cycles, and confining pressures in order to explore the effects of freeze-thaw cycles on the deformation and strength characteristics of cement improved loess.The results show that the cementation strength of the improved loess is greatly improved by the addition of cement, and the stress-strain curves of the improved loess show significant strain-softening characteristics.The nonlinear elastic model and elastic-brittle model are used to describe the deformation law of the improved loess.The initial tangent modulus and peak strength and cohesion of cement improved loess decrease significantly with the increase of freeze-thaw cycles times and the decrease of freezing temperature, and its deterioration effect of mechanical properties is significant when the number of freeze-thaw cycles times less than 6.In addition, response surface methodology is used to analyze the significance of each factor and their interaction.The results show that the confining pressure is the most significant factor affecting the peak strength change, followed by freeze-thaw times and freezing temperature.The interaction between confining pressure and freeze-thaw cycles times is the most significant when the interaction among influencing factors is considered.