  The signless Laplacian spectral radius of a graph $G$, denoted by $q(G)$, is
the largest eigenvalue of its signless Laplacian matrix. In this paper, we
investigate extremal signless Laplacian spectral radius for graphs without
short cycles or long cycles. Let $\mathcal{G}(m,g)$ be the family of graphs on
$m$ edges with girth $g$ and $\mathcal{H}(m,c)$ be the family of graphs on $m$
edges with circumference $c$. More precisely, we obtain the unique extremal
graph with maximal $q(G)$ in $\mathcal{G}(m,g)$ and $\mathcal{H}(m,c)$,
respectively.
