In this paper we introduce the concept of $gamma$-preopen sets in a topological space together with its corresponding $gamma$-preclosure and $gamma$-preinterior operators and a new class of topology $ au_{{gamma}p}$ which is generated by the class of $gamma$-preopen sets. Also we introduce $gamma$-pre $T_i$ spaces(i=0, $frac{1}{2}$, 1, 2) and study some of its properties and we proved that if $gamma$ is a regular operation, then$(X,;{ au}_{{gamma}p})$ is a $gamma$-pre $Tfrac{1}{2}$ space. Finally we introduce $(gamma,;eta)$-precontinuous mappings and study some of its properties.