Abstract：The rock-degradation and deterioration mechanism and mechanical characteristics have been studied through freezing-thawing test method. Three types of rocks(silty mudstone，diabase and dolomitic limestone) and two water environments(saturation by distilled water and erosion in 1% nitrate after saturation by distilled water) have been considered in the freezing-thawing test，which includes four-hour freeze and four-hour thaw in each cycle，eight hours in total. Uniaxial compressive strength test and quality analysis due to different cycles have been performed at the same time. It is shown that the freezing-thawing degradation and deterioration models of the rocks are affected by many factors：not only the self-characteristics of rock，freezing-thawing temperature and number of cycle，but also external environments. The test results show that the strength degradation due to cyclic freezing-thawing is greater in acidic environment than that in distilled water environment；and the results of freezing-thawing tests in distilled water environment often give an underestimation in the actual projects. The research conclusions can provide valuable references to the construction and the safety operation of similar projects in cold regions.
