Let G be a simple graph of order n. The hop domination polynomial of G is the polynomial Dh(G̦ x)=Σdh(G̦ i)xi|V(G)|i=γh(G), where dh (G, i) is the number of hop dominating sets of G of size i and γh(G) is the hop domination number of G. In this paper we study Dh (G, x) of a graph. We classify many families of graphs by studying their hop domination polynomial
