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Land degradation by water erosion, especially gullying, is a serious problem for grassland pastures on the Tibetan Plateau. Its extent and dynamics are still largely unknown. Erosion dynamics in the south of the Tibetan Plateau in the last century were analyzed by means of repeat photography. Twenty historical photographs covering the period from 1901 to 1939 were compared with recent photographs or simulated views using Google Earth. We focused on gullies and rills which can be easily recognized on the photographs. No significant changes could be identified by the comparison. Two sites documenting extensive denudation also feature no observable changes. Our results suggest that the form of pastoralism practiced in recent decades has not led to a significant increase of gullying activity in the study area.