In order to determine of potential forage productivity of cold-region alfalfa ecotypes and introduce superior ecotype for each location, this experiment was conducted with 17 ecotypes in Randomized Complete Block Design (RCBD) with three replication in 5 locations include Karaj, Esfahan, Tabriz, Mashad and Hamedan for 4 years during 2004-2008. Significant differences were found among total mean of fresh, dry forage yield, plant height in harvesting and leaf to stem ratio among tested locations. However, ecotypes have significant differences for fresh and dry forage yield. Also for all traits except dry forage yield, significant differences were found among three years. Interaction effects were significant especially for yields. Regarding to results, Esfahan with 124.76 and 27.25T/ha for fresh and dry forage yield was the best location corresponding to forage productivity. Three superior ecotypes corresponding to fresh and dry forage yield, plant height and leaf to stem ratio in all locations and years were as follows: Silvana, Galebani and Rahnani with 67.63, 67.22 and 66.98 T/ha for fresh forage yield, Ghahavand, Kozareh and Silvana with 18.69, 18.47 and 18.44 T/ha for dry forage yield, Galebani, Silvana and Sahandava with 72.06, 70.00 and 69.70 centimeter for plant height in harvesting and Silvana, Sahandava and Malek-kandi with 1.04, 1.02 and 1.02 for leaf to stem ratio respectively.