  By using thermal QCD sum rules to investigate the $\bar{\theta}$ induced
neutron electric dipole moment $d_n$, we have examined the behaviour of broken
CP symmetry at finite temperature. We find that, below the critical
temperature, the ratio $\mid {d_n \over \bar{\theta}}\mid$ slightly decreases
but survives at temperature effects, implying T nonrestoration of CP-invariance
\cite{Chabab}.
