To study the effects of concentration of de-icing salt on salt sacling, two groups of tests were conducted to research the relationship between the concentration of brine ice and the elastic modulus as well as the changes of concrete mechanical properties with the increase of freeze-thaw times. The first group of test was conducted on brine ice which were frozen from NaCL de-icing solution at the concentration of 0%,1%,3%,5% and 7%, respectively under uni-axial unconfined compressive load; while the other groups were conducted on concrete speciment with NaCL de-icing solution at the concentration of 0% and 3% freezing and thawing cycle test. Based on the test results, a reasonable explanation is discovered for the phenomenon that when the concentration of de-icing salt is moderate, the most serious salt scaling will occur.