  We study topological gauge theories with N=(2,0) supersymmetry based on
stable bundles on general Kahler 3-folds. In order to have a theory that is
well defined and well behaved, we consider a model based on an extension of the
usual holomorphic bundle by including a holomorphic 3-form. The correlation
functions of the model describe complex 3-dimensional generalizations of
Donaldson-Witten type invariants. We show that the path integral can be written
as a sum of contributions from stable bundles and a complex 3-dimensional
version of Seiberg-Witten monopoles. We study certain deformations of the
theory, which allow us to consider the situation of reducible connections. We
shortly discuss situations of reduced holonomy. Afterdimensional reduction to a
Kahler 2-fold, the theory reduces to Vafa-Wittentheory. On a Calabi-Yau 3-fold,
the supersymmetry is enhanced to N=(2,2). This model may be used to describe
classical limits of certain compactifications of(matrix) string theory.
