A description of mobile Ni contents in various subtypes of calcareous black soils from the area of the mountain massif of Rajac, is given in the present paper. A hundred soil samples were analysed in all, originating from four subtypes of calcareous black soil (organogenic, organo-mineral, brownized and loessivized black soils). The extraction of mobile Ni was carried out with 1.0 N HCl and its content was determined by atomic absorption spectrophotometry.