The appearance of spin polarized states (magnetic polarons) in hole do
ped CuO2 layers of the high-T-c systems is investigated. Starting from
a three-band Hubbard model which is treated in the Hartree-Fock and t
he slave-boson saddle-point approximation, respectively, the spin dist
urbed structure around a single hole is studied in detail. The change
of the spin cluster polarization towards metalization in dependence of
the hole concentration is discussed. Furtheron we investigate the com
petition between the formation of these self-localized one-particle st
ates with the occurence of correlated two-particle singlet states.