In order to explore the effects of different biostimulant substances on cotton at seedling stage，4 common biostimulant substances，including amino acid，alginic acid，γ-polyglutamic acid and molasses fermentation liquid，were selected and sprayed on cotton at seedling stage combined with the same nitrogen fertilizer(urea).The effects of different biostimulants on dry matter weight of different organs，stem diameter，plant height，leaf area and SPAD value of cotton at seedling stage were analyzed.The results showed that the whole plant dry matter weight，stem diameter，SPAD value and leaf area of cotton seedlings treated with foliar fertilizer were improved compared with water treatment.Combined application of biostimulant treatments promoted whole plant dry matter accumulation，stem girth and leaf expansion of cotton at seeding stage more obviously compared with urea treatment，and increased by 19.94% ～ 43.56%，1.43% ～ 18.05%，13.34% ～ 50.67%，respectively.Different biostimulants as foliar fertilizer base fluid additives at cotton seedling stage all had a certain degree of promoting effect，but γ-polyglutamic acid and molasses fermentation liquid had stronger promoting effect on dry matter，stem diameter，plant height and leaf area at cotton seedling stage.The leaf area and dry matter of per plant of urea application combined with γ-polyglutamic acid treatment were 149.36 cm2/plant and 4.68 g/plant，which were higher than those of other treatments.The stem diameter and plant height of urea application combined with molasses fermentation liquid treatment were 4.12 mm，15.75 cm，and were higher than other treatments.Therefore，urea combined with γ-polyglutamic acid or molasses fermentation liquid have significant effect on promoting the growth of cotton seedlings.