Abstract: in order to explore a water table fuctuation affcted to the slope stability atered rock samples were taken from the slope in Lazhou Ccangshang Surace/Mine ,raxial compression fests were conduced on the atered rock wth dfferent water saturation-dehyration ciculaton times. With the exploration on the variation law of each mechanics parameter a function relation establisied was applied to explan the mechanics property vaiation mode of thealtered rock affected by the water-ock circulation interaction and the damage probability conceapfion inroduced was aplild to analyze the ciculation tines afected to the mechanics propery of the alteed rock.The resuts showed that under the same water saturation-dehydration ciroulation times.the uitimate compressive strength of the altered rock would be increasd with the surounding rock pressure increased. Under the diferent croulation times.the cohesion foce of th atered rock would be raidly decreased with the cicu aton times inceased, and woud be in a sustained decreasing status.The damage of the intenal fiction angle and woult be weak. ith the alteration and broken degreencreased,the water-rock ineracion damaged to each mechanics propertyof the rock was continuously increased,the cohesion foce damage rate wasup to 70% and the damage rate of the inernal frcion angle was up to 30%. The water-rock interaction affected to the mechanics propery of th atered rok manly would be the coheson force reduction and the cohesion force variation of the altered rock would have high infuences to the slope steaility when the water table was fuctuated.