Abstract: Variation in geotemperature is one of the most important factors affecting the weathering process and the failure of shallow large of slope rockmass, the geotemperature field, which varies with the weather, is characterized by cyclic variation. Moreover, the thermal stress, was an alternative stress caused by geotemperature variation, can lead the fatigue failure of rockmass. In this paper, the distribution of geotemperature field and the thermal stress are analysed, the mechanism and criterion of fatigue failure are also discussed.