  In present work the effective singlet-triplet model for CuO2-layer on the
grounds of multiband p-d model of strongly correlated electrons is obtained.
The resulting Hamiltonian has a form of generalized singlet-triplet t-t'-J
model for p-type superconductors and form of usual t-t'-J model for n-type
superconductors. In the mean field approximation in X-operator representation
we derived equations for Gorkov type Green functions. The symmetry
classification of the superconducting order parameter in case of tetragonal
lattice resulted in d_{x^2-y^2}- and d_{xy}-types of singlet pairing for both
p- and n-type superconductors while s-type singlet pairing don't take place.
Also normal paramagnetic phase of effective singlet-triplet model was
investigated and dispersion over Brillouin zone, density of states and
evolution of Fermi level with doping were obtained.
