  A formula is given which computes the Seiberg-Witten invariant of a
3-orbifold from the invariant of the underlying manifold. As an application, we
derive a formula for the Seiberg-Witten invariant of a non-K\"{a}hler complex
surface, which was originally due to O. Biquard \cite{Biq} and S.R. Williams
\cite{W} independently.
