High levels of TDS in drinking water, has negative effects on broiler performance. Consumption of saline water results in increases blood pressure. In order to expulsion salt, water consumption increases, total amount of blood K decreases and an increment occurs in litter moisture. Consequently performance decreases, anion-cation becomes imbalance and some diseases such as ascites and coccidiosis happen. Change in anion-cation balance affects a lot of physiologic and metabolic functions of body, so can reduces performance and also increases FCR. Nowadays poultry producers in regions with high levels of NaCl in water, try to solve the problem by reducing NaCl content diet, purifying water or etc. Current study examined betaine supplementation for searching another way to get rid of this problem. Betaine implicated in methionine sparing and osmotic stress protection. It can protect intracellular proteins against hyper tonicity induced denaturation. Betaine is a naturally-occurring product present in relatively large quantities in sugar beet and aquatic invertebrates, but is not present in most animal feedstuffs (Wang et al., 2004). As a by-product of sugar beet processing, betaine is commercially available as a feed additive (Eklund et al., 2005).To date, concerning to our knowledge no information has been published about the osmolytic effects of betaine on performance and carcass traits of broilers in response to saline water consumption.