Abstract: The result showed that Vc content of onion increased,especially after applying Mofertilizer.And the soluble sugar had also been changed,its soluble sugar increased when Fefertilizer degree had been enhanced,but when we applied Zn or Mn fertilizer,the content ofsoluble sugar decreased evidently.At the same time,its microelements content changedobviously,Zn,Mn,Fe contents had been increased,but the content of Cu reduced in a largedegree.In addition,Ca and Mg contents also increased and the adsorption rate of P and K hadbeen enhanced because of microelement fertilization that will be benefit for its anticharactersand qualities.