2Department of Mathematics, Tarbiat Modares University, P. O. Box 14115-137, Tehran
The Hosoya index and the Merrifield-Simmons index are two types of graph invariants used in mathematical chemistry. In this paper, we give some formulas to compute these indices for some classes of corona product and link of two graphs. Furthermore, we obtain exact formulas of Hosoya and Merrifield-Simmons indices for the set of bicyclic graphs, caterpillars and dual star.