Abstract: In the present study the effect of 3 irrigation water (IW) salinities of 4, 8 and 12 dS m-1 were studied on grain yield and yield components of 6 wheat cultivars namely: Pishtaz, Shiraz, Mahdavi, Marvdasht, Kavir and Roshan during 2000 and 2002 growing seasons. The experiment was arranged in a split plot design, in four replicates, where irrigation water salinity and wheat cultivars were in the main plots and the sub-plots, respectively, in a silty clay loam soil. Increasing irrigation water salinity significantly decreased grain yield, number of spikes per square meter, plant height, grain filling duration and days to maturity. Based on mean productivity index (MP), geometric mean productivity index (GMP), stress tolerance index (STI) and stress susceptibility index (SSI); Roshan cultivar (a local grown cultivar, selected from local land races) was the most tolerant and stable cultivar in a wide range of irrigation water salinity levels. The Roshan mean grain yield was 4.237 Mg ha-1 in three IW salinity levels.