  We study the fluctuation of the eigenvalue number of any fixed interval
$\Delta=[a,b]$ inside the spectrum for $\beta$- ensembles of random matrices in
the case $\beta=1,2,4$. We assume that the potential $V$ is polynomial and
consider the cases of any multi-cut support of the equilibrium measure. It is
shown that fluctuations become gaussian in the limit $n\to\infty$, if they are
normalized by $\pi^{-2}\log n$.
