The types of the products of the reactions between RuH(NO)(Cyttp) and alkynes are sensitive to the nature of alkynes. Terminal, nonactivated alkynes (HC${equiv}$CR, R=Ph, hexyl and $CH_2OH)$ produce acetylide complexes and terminal (HC${equiv}$CR, R=C(O)Me, COOEt) or internal activated ones (RC${equiv}$ CR, R=COOMe) lead to form alkenyl complexes. On the other hand, internal nonactivated alkynes (RC${equiv}$CR, R=Ph) do not show reactivity toward RuH(NO)(Cyttp). These products can be rationalized by the cis-concerted mechanism but the radical pathway appears to work in the reaction of propargyl chloride. From the spectroscopic data, the trigonal bipyramidal structure with a linear NO group is proposed for these products.