Abstract: According to the statistic data, of all the accidents, about 1/3 are caused by floodwaters. Tailing dam is a main facility of tailing reservoir and its stability is very relevant to water. The study of dam stability is a very complicated issue and involves a series of variables difficult to accurately determine such as underwater level, rainfall, mechanics parameters etc. As is commonly known, accidents such as landslide and dam failure are often closely related to water. However, such relation has not been fully recognized and understood. In view of the water's important effect on the safety operation of tailing dam, the paper describes the two ways in which water affect the dam slope and discusses water's effect in the dam stability and its mechanism in relation to the water role in landslide disaster.

Key words: Tailing dam, Stability, Permeability