To evaluate agronomic potential of grass-pea vine (Lathyrus sativus L.) under arid and semi-arid conditions, 14 lines selected from preliminary comparisons were investigated in a randomized complete block design with three replications at Gachsaran Rainfed Research Station Center (GRRSC) during 2005-2007. The combined analysis of variance reaveled that the effect of genotype, year and interaction of genotype by year were significant for most traits under investigation. Because of low rainfall in 2007 year, the values of traits measured were lower than those of two previous years. Three year means showed that green forage yields were between 13719 and 21294 kg ha-1, biological yields ranged between 4670 and 6789 kg ha-1, grain yield between 1257 and 1616 kg ha-1, straw yield between 3297 and 5067 kg ha-1, 100-grain weight between 9.2 and 13 g and harvest index between 23.9 and 30.3%. It can be concluded that, line Sel.736 for green forage and dry forage yield and line Sel.1307 for grain yield were high producers.