Аннотация:We study magnetic susceptibility and magnetization curves of Pb1-x-yGexYbyTe diluted magnetic semiconductors. It is found that magnetic susceptibility of the alloys contains two principal contributions: the temperature independent diamagnetic and the paramagnetic, growing according to the Curie-Weiss law as temperature decreases. Concentration of magnetic Yb3+ ions, determined from the Curie constant, increases with ytterbium doping, nevertheless, the fraction of magnetic ions does not exceed 30 % of the total ytterbium content. We explain the experimental results obtained using the model of charge carrier energy spectrum in Pb1-x-yGexYbyTe. In frame of this model we describe a kinetics of magnetic ion formation with doping and determine an electron population of the ytterbium deep states.