  Let $M$ be a real $l$-dimensional minimal submanifold with flat normal
connection in a kaehler product manifold $\overline{M}^m\times \overline{M}^n$
where $\overline{M}^m$ and $\overline{M}^n$ are complex $m$-dimensional and
complex $n$-dimensional kaehler manifolds with constant holomorphic sectional
curvature $c_1$ and $c_2$ respectively. We give a formula for the Laplacian of
the second fundamental form of $M$. Specially we discuss the F-anti invariant
case. We also give some applications of this formula.
