Abstract: 【Objective】 To study the effects of different fertilizing amounts on the yield formation of six Xinluzao cotton varieties, and to clarify the impact of reduced fertilizer application on the yield and quality of cotton cultivars in the hope of providing a basis for the breeding and cultivation of cotton varieties with low fertilizer tolerance. 【Methods】 Under field conditions, the agronomic traits, dry matter accumulation, yield quality and fertilizer utilization characteristics of 6 cotton varieties in the Xinluzao series were studied under three conditions: fertilizing amount applied in conventional production (N 193.2 kg/hm², P₂O₅ 138 kg/hm² and K₂O 85.5 kg/hm²),1/2 amount of fertilizer applied in conventional production, and no fertilization. 【Results】 There was no significant difference in branch number among the varieties of Xinluzao. In terms of plant height, branch number and stem diameter, the varieties with the lowest sensitivity to fertilization were Xinluzao 45, 61 and 45, respectively. The distribution rate was less affected by the amount of fertilizer applied. The varieties with the lowest sensitivity to the amount of fertilizer applied in terms of total biomass and allocation rate were Xinluzao 61 and 57, and the varieties with the highest sensitivity were Xinluzao 74 and 72, respectively. The number of bolls per plant and the seed cotton yield increased with the increase of the amount of fertilizer applied, and the lint percentage decreased with the increase of the amount of fertilizer applied. The varieties with the lowest sensitivity in terms of boll number per-plant, boll weigh, lint percentage and seed cotton yield to the amount of fertilizer applied were Xinluzao72, Xinluzao 74 and Xinluzao 57; As the amount of fertilizer applied increased, the upper half mean length increased and the micronaire decreased. The varieties with the lowest sensitivity in terms of fiber strength, fracture specific strength and micronaire to fertilizer application were Xinluzao 57, 64 and 72, respectively. During the boll opening stage, the utilization rate of fertilizer agronomy and the contribution rate of fertilizer were proportional to the amount of fertilizer, and the partial productivity of fertilizer was inversely proportional to the amount of fertilizer applied. 【Conclusion】 Xinluzao 64, 72 and 74 have good performance in the aspects of lint percentage, fertilizer utilization rate and yield, respectively, and can be used as the cultivation varieties of reduced fertilizer application.