\documentclass[12pt]{article} \usepackage{amsmath,mathrsfs,bbm} \usepackage{amssymb} \textwidth=4.825in \overfullrule=0pt \thispagestyle{empty} \begin{document} \noindent % % {\bf Yun-Ping Deng and Xiao-Dong Zhang} % % \medskip \noindent % % {\bf Automorphism Group of the Derangement Graph} % % \vskip 5mm \noindent % % % % In this paper, we prove that the full automorphism group of the derangement graph $\Gamma_n$ ($n\geq3$) is equal to $(R(S_n)\rtimes\hbox{\rm Inn} (S_n))\rtimes Z_2$, where $R(S_n)$ and $\hbox{\rm Inn} (S_n)$ are the right regular representation and the inner automorphism group of $S_n$ respectively, and $Z_2=\langle\varphi\rangle$ with the mapping $\varphi:$ $\sigma^{\varphi}=\sigma^{-1},\,\forall\,\sigma\in S_n.$ Moreover, all orbits on the edge set of $\Gamma_n$ ($n\geq3$) are determined. \end{document} .