This report deals with results from an investigation in the Göta River Valley on the importance of salt content on the geotechnical properties of marine clays. Salt distribution in slopes is discussed and the method to determine slip surfaces in slides by means of salt soundings. The leaching theory has been studied both in the field and in the laboratory. No relation seems to exist between the total salt content in the pore water and the sensitivity. A relation seems, however, to exist between the chemical composition of the pore water salt and the sensitivity. Leached non quick clays contain relatively more divalent ions in the pore water than the quick clays. It can be shown that calcium and magnesium are complex bound in the quick clay system by means of organic material. The Donnan condition is thus valid for a quick clay system in spite of the apparent deviation. Ageing phenomena in quick clays are discussed. These properties seem to be in opposition to the classical leaching theory. Diffusion in natural slopes can be studied from the sharp salt gradient formed in a slide and some diffusion studies are reported. The connection between diffusion and electrical conductivity is also treated. The pure diffusion in Göta River clays seems to be too small for a commercial chemical stabilization. Other possible stabilization methods are also discussed.