The performance of concrete with a new admi xt ure MX was studied by using the freeze-thaw cycle, permeability and chemical at tack test. The experimental results show that MX improves the durability of conc re te. Within the optimum proportion ranges from 0.1%to 1%,the compressive strength of concrete after freeze-thaw is increased by 20%-50%,and Young's modulus can be increased by 3.76-5.64 times.The strength and weight loss of concrete with 0.4%MX are respectively decreased by 28% and 60% after hydrochloric acid attack. The strength and weight loss of concrete with 0.4% MX are decreased by 5%-20% a fter sulfuric acid and sodium sulfate attack.The permeability of concrete with 1 % MX at 28 days can be decreased by more than 30%. The investigation of the nega tive temperature property of MX and analysis on concrete composition and microst ructure by MIP reveal that the heat conduction is resisted and the freezing proc edure of solution in concrete pore is retarded due to the adding of MX. Moreover ,the pore structure of concrete with MX is improved, thus improving the durabili ty. Based on this study, a resistance model of MX to block the heat and mass tra nsference was proposed, and the mechanism of durability improvement of concrete with MX was explained. The performance of concrete with a new admi xt ure MX was studied by using the freeze-thaw cycle, permeability and chemical at tack test. The experimental results show that MX improves the durability of conc re te. Within the optimum proportion ranges from 0.1% to 1%, the compressive strength of concrete after freeze-thaw is increased by 20% -50%, and Young's modulus can be increased by 3.76-5.64 times. Strength and weight loss of concrete with 0.4% MX are separately decreased by 28 % and 60% after hydrochloric acid attack. The strength and weight loss of concrete with 0.4% MX are decreased by 5% -20% a fter sulfuric acid and sodium sulfate attack. The permeability of concrete with 1% MX at 28 days can be decreased by more than 30%. The investigation of the nega tive temperature property of MX and analysis on concrete composition and microst ructure by MIP reveal that the heat conduction is resisted and the freezing proc edure of solution in concrete pore is retarded due to the adding of MX. Moreover, the pore structure of concrete with MX is improved, thus improving the durabili ty. Based on this study, a resistance model of MX to block the heat and mass tra nsference was proposed, and the mechanism of durability improvement of concrete with MX was explained.