  We propose to resolve the controversy regarding the stability of the monopole
condensation in QCD by calculating the imaginary part of the one-loop effective
action perturbatively. We calculate the imaginary part perturbatively to the
order $g^2$ with two different methods, with Fyenman diagram and with
Schwinger's method. Our result shows that with the magnetic background the
effective action has no imaginary part, but with the electric background it
acquires a negative imaginary part. This strongly indicates a stable monopole
condensation in QCD.
