The economic value of a plant depends on the values of its different characters and plant breeders have hence considered simultaneous selection of multiple traits to improve the economic value of the crop. The most desirable approach to improve characteristics such as yield with polygenic inheritance and genotype × environment interaction, is simultaneous selection using selection index based on related traits and consideration of their economic weights, heritabilities and also their genetic and phenotypic correlations. This study was conducted at Research Farm of Isfahan University of Technology, to compare selection indices for barley yield improvement under nitrogen stress and non stress conditions, using 49 F13 recombinant inbred lines derived from a cross between Azumamugi (AZ) and Kanto Nakate Gold (KNG). A split plot design with randomized complete block layout was used having three replications. In non-stress condition 100 kg nitrogen per hectare in urea manure was used as topdressing at early reproductive growth, stem elongation and grain filling stages. In stress condition, 50 kg nitrogen per hectare was only used at early vegetative growth stage. The result indicated that there was enough genetic variation in all traits under both stress and non stress conditions. Nitrogen stress decreased all the traits except nitrogen harvest index. Considerable reduction in straw protein, grain yield, biological yield and growth rate was observed due to nitrogen deficiency. Therefore, it is suggested to employ these traits in screening for tolerance to nitrogen stress. There was significant difference among lines for all stress tolerance and susceptibility indices for straw nitrogen content and nitrogen harvest index. But for grain nitrogen content there were only significant differences for mean productivity, geometric mean productivity and stress tolerance index. These indices had also the highest correlations with all these three traits. Applying stress tolerance indices for all the three traits, lines 23, 30, 65 and 66 can be introduced as nitrogen stress tolerant lines and line 93 as stress susceptible. Based on nitrogen use efficiency indices, line 30 was also considered as an efficient genotype. The result of direct and correlated responses to selection showed that selection for higher harvest index and nitrogen harvest index, in both conditions screens high yielding lines. Using Smith-Hazel and Psek-Baker indices based on 5 (days to heading, grain nitrogen, straw nitrogen, harvest index and growth rate) and 4 (days to heading, harvest index, growth rate and nitrogen harvest index) traits, line 92 was the superior line under both stress and non stress conditions. According to stress tolerance and susceptibility indices, this line was also among the tolerant lines. under both conditions and for Smith-Hazel and Psek-Baker indices based on 5 traits, days to heading, grain nitrogen, harvest index and growth