Abstract: Let G=(V,E) be a simple graph. For a subset $S\subseteq V$, let G[S] denote the subgraph of G induced by S. S is a paired-dominating set of G if S is a dominating set of G and G[S] contains at least one perfect matching. The paired domination number, denoted by γ_p(G), is the minimum cardinality of a paired dominating set of G. In this paper, the authors show that for any
cubic graph G of order n, γ_p(G)≤3n/ 5.

Key words: Paired domination number, Cubic graph, Private neighbor