Abstract: 【Objective】 A field experiment was conducted to evaluate the nitrogen fertilizer reduction on NH₃ volatilization, nutrient use and cotton yield in drip-irrigated cotton field. 【Methods】 The experiment consisted of 5 fertilization treatments: control (no N fertilization, CK), farmer conventional fertilization (300 kg/hm², T₃₀₀), conventional fertilization N reduced by 20% (240 kg/hm², T₂₄₀), acid liquid fertilizer N reduced by 20% (240 kg/hm², L₂₄₀), acid liquid fertilizer N reduced by 35% (200 kg/hm², L₂₀₀). 【Result】 The volatilization loss of soil NH₃ in nitrogen reduction treatment (T₂₄₀, L₂₄₀, L₂₀₀) was 31.1%, 73.4% and 78.8% lower than that in T₃₀₀ treatment, respectively. At the same N application level, NH₃ volatilization accumulation in L₂₄₀ treatment was 61.4% lower than that in T₂₄₀ treatment. The nitrogen uptake of T₂₄₀ and L₂₄₀ treatments was significantly better than that of T₃₀₀ treatment, which increased by 9.1% and 12.6%, respectively, compared with T₃₀₀ treatment. The phosphorus uptake of cotton treated with L₂₄₀ was the highest in each treatment, which was 11.7%-17.7% higher than those of other treatments. The yields of cotton in T₂₄₀ and L₂₄₀ treatments were significantly higher than that in the T₃₀₀ treatment, which increased by 9.6% and 12.6%, respectively. Compared with T₃₀₀ treatment, each nitrogen reduction treatment improved the nitrogen fertilizer utilization rate of cotton, in which the apparent nitrogen fertilizer utilization rate increased by 20.1% to 24.9%. 【Conclusion】 Acid liquid fertilizer N reduced by 20% significantly reduced NH₃ volatilization loss, promoted nitrogen and phosphorus uptake in cotton and increased cotton yield and fertilizer use efficiency.