Due to the dry climate and limitation of fresh water resources, using fresh and salt water is a solution for crop production under salinity conditions. Sorghum is a semi resistant to salinity and it will grow economically in this conditions.This study was conducted in Isfahan University of Technology as a randomized complete block design with three replications and five irrigation management treatments in 2014. The treatments including irrigation with saline water (with salinity of 5 dS/m,based on the relative yiled of 75%), irrigation with fresh water (municipal water), alternate irrigation (irrigation with saline water and next irrigation with fresh water), conjunctive irrigation (half of irrigation with saline water and the other half with fresh water) and irrigation with fresh water to the raceme stage, then irrigation with saline water. Grain sorghum was planted in sandy clay loam soil. The results show that the effect of irrigation management on yield was significant at level of 1%. Increasing salinity had a significant effect on the wet, dry and grain yield, weight of thousand grain and panicle length. The maximum wet yield, dry yield and grain yield, were related to fresh water treatment with 4.14, 2.45 and 0.588 kg/m 2 and the minimum value were, related to salt water their water treatment with 1.34, 0.765 and 0.0957 kg/m 2 respectively. The conjunctive treatment had the highest yield after of fresh water treatment. The results show that the use of salt water in the plant cluster stage reduced grain yield and weight thousand grain. Analysis of variance showed that the effect of treatments were significant on amount of potassium concentration of plant at level of 5%, on potassium concentration of grain, sodium concentration of plant and sodium concentration of grain at level of 1%. The amount of potassium concentration in the plant, will decreased with increasing salinity. The maximum amount of potassium concentration in plant with fresh water treatment was 0.744 mg per g dry weight, and the minimum amount of potassium concentration in plant with salt treatment was 0.515 mg per g dry weight. The maximum amount of sodium concentration in plant with salt treatment was 23.85 mg per g dry weight, and the minimum amount of sodium concentration in plant with fresh treatment was 18.10 mg per g dry weight. The Sodium concentration cations in the soil, had the highest amount with at depth of 20-40 cm was 74.16 meq/lit. The effect of different treatment on, sodium, calcium and magnesium concentration were significantly, but there was no significant difference on potassium concentration. The highest amount of anions was related to clorid concentration that at depth of 20-40 cm observed with 68.00 meq/lit. Data input to the SWAP model were meteorological data includy daily solar radiation, maximum and minimum air temperature, relative humidity, wind speed, irrigation data including irrigation schedule and concentration of salts in irrigation, crop data including herbal calendar the emergence and harvest date and soil data including depth of soil layers and their textures. The determination coefficients for yield and output salt were 0.65 and 0.81 respectively. The various statistical indicec show that this model can be used for sorghum in Isfahan. Keywords : Fresh Water, Salt Water, Conjunctive Irrigation, Grain Sorghum Yield, SWAP Model