Document Type: Research Paper
Yazd University, Iran
If is a connected graph with vertex set , then the eccentric connectivity index of , , is defined as Σ deg where deg is the degree of a vertex and is its eccentricity. Let A, B and C are families of graphs made by joining to , made by putting instead of each vertex in and made by putting instead of each vertex in , respectively. In this paper we compute the eccentric connectivity index of these families of graphs.