To evaluate the genetic variation of advanced and breeder lines of barley and to identify drought tolerant genotypes, 20 genotypes were tested in a randomized completely block design (RCBD) with three replications under two different water regimes (Irrigated and rainfed) in College of Agriculture, Razi University during 2007-2008 sowing season. The results of ANOVA showed that there were significant differences between grain yields (Yp and Ys) and some drought resistance indices such as mean productivity (MP), geometric mean productivity (GMP), harmonic mean (HAM), stress tolerance index (STI), yield index (YI) (p<0.01), yield stability index (YSI), and stress susceptibility index (SSI) (p<0.05). Study on correlation between Yp, Ys and other indices showed that GMP, STI, YI, HAM and MP were the most suitable drought tolerance criteria for screening of barley genotypes. Drawing of bi-plot based on two principal components indicated that genotypes number 14 and 17 were in area with high potential of production and next to vectors of MP, GMP and STI and distribution of genotypes in bi-plot represented the genetic diversity among genotypes for selecting them based on drought tolerance. According to GMP, STI, HAM and MP indices, lines No. 14, 15 and 17 had higher grain yield in two water regimes and identified as drought tolerant genotypes in conditions of Kermanshah.