  The generalized $k$-connectivity of a graph $G$, denoted by $\kappa_k(G)$, is
a generalization of the traditional connectivity. It is well known that the
generalized $k$-connectivity is an important indicator for measuring the fault
tolerance and reliability of interconnection networks. The $n$-dimensional
folded hypercube $FQ_n$ is obtained from the $n$-dimensional hypercube $Q_n$ by
adding an edge between any pair of vertices with complementary addresses. In
this paper, we show that $\kappa_3(FQ_n)=n$ for $n\ge 2$, that is, for any
three vertices in $FQ_n$, there exist $n$ internally disjoint trees connecting
them.
