  It is argued that the dominant contribution to the interaction of quark gluon
plasma at moderate $T\geq T_c$ is given by the nonperturbative vacuum field
correlators. Basing on that nonperturbative equation of state of quark-gluon
plasma is computed and in the lowest approximation expressed in terms of
absolute values of Polyakov lines for quarks and gluons $L_{fund} (T);
L_{adj}(T)=(L_{fund})^{9/4}$known from lattice and analytic calculations. Phase
transition at any $\mu$ is described as a transition due to vanishing of one of
correlators, $ D^E(x)$, which implies the change of gluonic condensate $\Delta
G_2$. Resulting transition temperature $T_c(\mu)$ is calculated in terms of
$\Delta$$G_2$ and $L_{fund}(T_c)$. The phase curve $T_c(\mu)$ is in good
agreement with lattice data. In particular $T_c(0)=0.27; 0.19; 0.17$ GeV for
$n_f=0,2,3$ and fixed $\Delta G_2=0.0035$ GeV$^4$.
