Abstract: To investigate the effects of different nitrogen fertilizer application ratios on nitrogen use efficiency, leaf senescence characteristics, and yield of cotton under different planting patterns, aiming to provide a rational fertilization strategy for high-yield and efficient cultivation of cotton in Xinjiang cotton-growing areas. The study used the ‘Xinluzhong 84’ variety as the research object and conducted field experiments in Hailou Town, Shayar County, Xinjiang from 2022 to 2023. A split-plot design was employed with two main planting patterns: one film with six rows (66+10) cm wide narrow row spacing, plant spacing of 12 cm (M6), and one film with three rows with 76 cm equal spacing, plant spacing of 6 cm (M3). Four nitrogen fertilizer application ratios were used as subplots: 0∶0 (CK, no nitrogen application), 0∶10 (N0), 2∶8 (N2), and 4∶6 (N4), totaling eight treatments. The total nitrogen application rate for all nitrogen treatments was 320 kg∙hm⁻². Nitrogen metabolism enzyme activity, leaf senescence-related enzyme activity, nitrogen use efficiency, yield, and yield components were measured. The results showed that in 2022~2023, the yield of seed cotton could be higher in M3N4 treatment, which reached 7342.59 kg∙hm⁻² and 8085.19 kg∙hm⁻², respectively, which was 12.05% and 6.18% higher than that of M6N2 treatment (M6 optimal yield treatment). Compared with M6N2 treatment, the number of boll per plant increased by 10.17%, but the weight per boll decreased by 1.48% on average. M3N4 treatment could maintain a high content of physiologically active enzymes, promote the level of nitrogen metabolism in cotton, and prolong the functional period of cotton leaves at the full flowering and boll stage. Compared with the M3 model, the maximum nitrogen accumulation rate (V_m) of the M6 model was increased, but the occurrence time (T) of the maximum nitrogen accumulation rate was slightly delayed, the duration of rapid growth (∆t) decreased by 3.85~11.64 days, and the growth characteristic value (T_G) of nitrogen growth period decreased by 4.23%~27.60%. The total nitrogen accumulation of cotton plants in each nitrogen fertilizer treatment under the M3 mode was higher than that of the corresponding nitrogen fertilizer treatment in the M6 mode, and the nitrogen accumulation in vegetative organs in the M3N4 treatment was significantly higher than that in the other treatments. Compared with M6N2 treatment, the agronomic use efficiency, nitrogen recovery rate and partial productivity of cotton fertilizer in M3N4 treatment increased by 7.77%, 10.56% and 8.90%, respectively, but the physiological use efficiency of nitrogen fertilizer decreased by 3.03%.Reasonable nitrogen base chasing ratio and planting pattern can regulate the contradiction between individual and group cotton plants, accelerate nitrogen metabolism levels, increase nitrogen accumulation and transport in various plant organs to enhance nitrogen use efficiency, boost physiological enzyme activity to delay leaf senescence in cotton plants, maintain a higher boll number per plant, and fully exploit cotton production potential. Under this experimental conditions, planting mode with 76 cm equal spacing and a nitrogen fertilizer application ratio of 4:6 were identified as the optimal combination for increasing yield.