In this work, we report the results of density functional theory calculations of ethylene and acetylene adsorption on the most stable Cu-n (n=10-15) nanoclusters, in two pi and di-sigma-adsorption modes. Both the hydrocarbons molecularly adsorbed on the surface. Our results show that the quality of interaction of ethylene and acetylene with odd copper nanoclusters (n =11, 13, 15) is different from what is found on even copper nanoclusters (n =10, 12, 14). One of the interesting features of this adsorption is that acetylene never orient toward di-sigma mode for Cu-Cu bond in odd copper nanoclusters. Also, for di-sigma, CunC2H4, no stable structure is identified. The highest interaction and deformation energies are seen for the adsorption of acetylene and ethylene on Cu-11 in pi-mode. (C) 2016 Elsevier B.V. All rights reserved.