A great deal of paleoenvironmental research on tropical alluvia and slope sediments assumed the long-term persistence of stable climates and associated rainforest vegetation in the Congo basin during the Quaternary. Geomorphological, paleo-hydrological and ecosystem history research in the eastern Congo basin (Kivu, DR Congo) has provided evidence of the frequent occurrence of multi-layered alluvia and fans in river valleys and plains as well as stratified slope deposits (hill-wash, stone-lines, pedo-sediments) that reflect former modifications of the environment. Numerous radiocarbon data indicate that ecosystems within the Congo basin are highly sensitive to climate change through modification of surfaces and run-off dynamics. A stratigraphic record characterized by variable sediment layers of 2.0–5.5 meters thick spans the Holocene and the Pleistocene back to 50 ka BP (completed by finds from Cameroon and Central African Republic). Buried stone-lines and paleo-soils indicate once drier, more open landscapes under alternating wet and dry climates in currently humid and semi-humid regions. A conceptual morpho-dynamic model is presented and summarizes process related response to former environmental modifications.