tIn this work, we report the results of density functional theory calculations of ethylene and acetyleneadsorption on the most stable Cun(n = 10–15) nanoclusters, in two and di- adsorption modes. Boththe hydrocarbons molecularly adsorbed on the surface. Our results show that the quality of interactionof ethylene and acetylene with odd copper nanoclusters (n = 11, 13, 15) is different from what is foundon even copper nanoclusters (n = 10, 12, 14). One of the interesting features of this adsorption is thatacetylene never orient toward di- mode for Cu Cu bond in odd copper nanoclusters. Also, for di- -CunC2H4, no stable structure is identified. The highest interaction and deformation energies are seen forthe adsorption of acetylene and ethylene on Cu11in -mode.