Density　functional　theory　calculations　have　been　performed　to　study　the　interaction　of　small　silver　clusters,　Ag-2　similar　to　Ag-9,　with　HCN.　The　adsorption　of　HCN　on-top　site　of　the　silver　cluster,　among　various　possible　sites,　is　energetically　preferred.　The　adsorption　energies　of　HCN　on　the　silver　clusters　reach　a　local　maximum　at　n　=　4,　which　is　only　about　0.450　eV,　indicating　that　the　adsorbed　HCN　molecule　is　weakly　perturbed.　The　adsorbed　C-N　and　C-H　stretching　frequencies　are　blue-　and　red-shifted　compared　with　the　values　of　free　HCN,　respectively.