Human subjects estimated the saltiness of sodium chloride and a mixture of sodium chloride and sucrose. The adapting effects of sucrose, sodium chloride and a mixture of both substances were investigated. The stimuli were delivered by a flow system to pre-defined tongue areas. After adaptation to NaCl and to the mixture the subjective intensity of NaCl-saltiness decreased 58% and 69% respectively. Also a strong masking effect of saltiness was observed: 59.1% reduction. No indications of crossadaptation were found. The results were interpreted in favour of the independency of adaptation and masking.