Let G be a simple connected graph. In this paper, Szeged dimension and PIv dimension of graph G are introduced. It is proved that if G is a graph of Szeged dimension 1 then line graph of G is 2-connected. Trees of Szeged dimension 1 are characterized. The Szeged dimension and PIv dimension of five composite graphs: sum, corona, composition, disjunction and symmetric difference with strongly regular components are computed. Also explicit formulas of Szeged and PIv indices for these composite graphs are obtained.