Abstract: With the increase of corrosion and freeze-thaw cycles, the changes in the parameters of concrete with initial damage were experimentally studied, including mass, ultrasonic velocity and compressive strength. The quantitative evaluation and parameter fitting was made based on damage mechanical theory. The changes of concrete microstructures were analyzed using the environmental scanning electron microscopy（ＥＳＥＭ）. The research results show that: with the increase of corrosion and freeze-thaw cycles, the mass of concrete increases first and then decreases, and ultrasonic velocity and compressive strength of concrete gradually is reduced. The initial damage exacerbates deterioration of concrete. The action of freeze-thaw plays a leading role in the damage and deterioration of concrete and brings the more and greater destructive effect than corrosion. Under the action of freeze-thaw, the initial damage has an more obvious impact on deterioration of concrete. The action of sulfate attack and freeze-thaw leads to the formation and connection of micro-cracks inside concrete. The existence of initial damage leads to more developed micro-cracks network which extends and expands continuously.