  For a graph $G$ without isolated vertices, the inverse degree of a graph $G$
is defined as $ID(G)=\sum_{u\in V(G)}d(u)^{-1}$ where $d(u)$ is the number of
vertices adjacent to the vertex $u$ in $G$. By replacing $-1$ by any non-zero
real number we obtain zeroth-order general Randi\'c index, i.e.
$^0R_{\gamma}(G)=\sum_{u\in V(G)}d(u)^{\gamma}$ where $\gamma$ is any non-zero
real number. In \cite{xd}, Xu et. al. determined some upper and lower bounds on
the inverse degree for a connected graph $G$ in terms of chromatic number,
clique number, connectivity, number of cut edges. In this paper, we extend
their results and investigate if the same results hold for $\gamma<0$. The
corresponding extremal graphs have been also characterized.
