  Let $p$ be a prime, $S$ be a $p$-group and $\mathcal{F}$ be a saturated
fusion system over $S$. Then $\mathcal{F}$ is said to be supersolvable, if
there exists a series of $S$, namely $1 = S_0 \leq S_1 \leq \cdots \leq S_n =
S$, such that $S_{i+1}/S_i$ is cyclic, $i=0,1,\cdots, n-1$, $S_i$ is strongly
$\mathcal{F}$-closed, $i=0,1,\cdots,n$. In this paper, we investigate the
characterizations for supersolvability of $\mathcal{F}_S (G)$ under the
assumption that certain subgroups of $G$ satisfy different kinds of generalized
normalities in section \ref{1003}. Moreover, we obtain the more advanced and
remarkable result of characterizations for generalized saturated fusion system
$\mathcal{F}$ in section \ref{Section 4}. Finally, we apply the results in
section \ref{1003} and \ref{Section 4} and give characterizations for
$p$-nilpotency of finite groups under the assumption that some subgroups of $G$
satisfy different kinds of generalized normalities.
