  The concept of resistance distance was first proposed by Klein and Randi\'c.
The Kirchhoff index $Kf(G)$ of a graph $G$ is the sum of resistance distance
between all pairs of vertices in $G$. A connected graph $G$ is called a cactus
if each block of $G$ is either an edge or a cycle. Let $Cat(n;t)$ be the set of
connected cacti possessing $n$ vertices and $t$ cycles, where $0\leq t \leq
\lfloor\frac{n-1}{2}\rfloor$. In this paper, the maximum kirchhoff index of
cacti are characterized, as well as the corresponding extremal graph.
