Abstract: This study investigated the effects of nitrogen fertilizer on the forage yield and quality of Italian ryegrass (Lolium multiflorum) in saline soil and non-saline soil conditions. The experiment was carried out at Jinhai Farm, Liuhe Experiment Station, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu Province. Nitrogen fertilizer treatments were; N₀ (Control), N₁ (100 kg/ha), N₂ (150 kg/ha) and N₃ (200 kg/ha). Pasture was sampled at the stem elongation (first cut) and heading stages (second cut) and assessed for yield and quality related straits. The results indicated that the effects of nitrogen on grass yield and forage quality in saline soil and non-saline soil were different; yield and quality of Italian ryegrass in non-saline soil were better than those in saline soil. In vitro dry matter digestibility (IVDMD), crude protein (CP) and nonstructural carbohydrates (NSC) content of Italian ryegrass in non-saline soil were higher than those in saline soil, and higher from the first cut than the second cut. The CP content increased with increasing nitrogen application while NSC content decreased with increasing nitrogen. Starch content from saline soil was higher than non-saline soil. The IVDMD of nitrogen treatments was higher than that of the control but there were no differences between nitrogen treatments. The neutral detergent fiber (NDF) content of Italian ryegrass in saline soil was higher than that in non-saline soil and higher in the second cut than the first. Dry matter (DM) of Italian ryegrass in saline soil was significantly higher than that in non-saline soil, and that of the second cut higher than the first. The forage yield in non-saline soil was higher than that of saline soil, and that of the second cut higher than the firs. Grass yield increased with increasing nitrogen fertilizer but yield responses to nitrogen were in saline soil were higher than that in non-saline soil.