The effect of the wheat straw mulching and phosphate fertilizer，seaweed fertilizer on cotton yield and fiber quality of cotton was studied on the specific site for three years in the Huang huai hai plain typical saline alkali area，and the mathematical model between the three factors and seed cotton yield was established respectively.The results showed that there are significant typical fertilizer effect function relationships between these three factors and seed cotton yield.Covering straw can increase fiber length of cotton，and moderate amount of phosphate (P2O5) helps to improve the fiber breaking tenacity.More seaweed fertilizer could improve the fiber length，reflectivity，and elongation.All three factors have little effects on the degree of fiber micronaire，yellow degree and uniformity index.To gain high yield which is more than 2 250 kg·hm-2，8 180.4～8 748.0 kg·hm-2 of straw covering，117.8～141.5 kg·hm-2 of phosphate fertilizer (P2O5),or 738.8～922.0 kg·hm-2of seaweed fertilizer are required.As for the application methods，100% phosphorus fertilizer and 50% of seaweed fertilizer was used as basal，and the other 50% seaweed fertilizer was applied as topdressing.Wheat straw was covered in row uniformly during the cotton blooming period.