Abstract: In order to study the effects of biochemical fulvic acid potassium on crop growth,maize Zhengdan 958was taken as the research object to explore the effects of fertilizers with different biochemical fulvic acid potassium contents on maize root,stem and biomass.The results showed that adding 5.0-8.0kg·t^-1 biochemical fulvic acid potassium to the fertilizer could significantly promote the growth of root,stem and reproduction of maize.Under the condition of adding 8.0kg·t^-1,the effect of fertilizer was the most significant and stable.Compared with the fertilizers common control,it increased the fresh weight of maize roots by 35.3%,significantly increased the biomass of maize by 12.3%,and increased the stem diameter of maize during the growth period by 5.0%-21.7%.In conclusion the fertilizer added with 8kg·t^-1 biochemical fulvic acid potassium can promote the growth of maize,so it can be used as a quality improling fertilizer for specific maize production.