Abstract: In the method of water culture，the influences of Mn deficiency，low Mn and normal Mn on the growth and development of wheat were studied．The results show that with the Jingdong-8，both the low Mn and the Mn deficiency make the fresh weight and the dry weight of stem an d root decrease obviously，the content of the N0₃^--N and the soluble protein increase evid/ently；while the content of amino acid has no obvious difference in other trea tments，except for the marked decrease at the lower Mn concentration of 0．001umol/L；al1 the indexes express that 1ow Mn concentration has more higher influence than Mn deficiency；in protein electropho resis，two protein lines disappear in the low Mn concentration．The expressions 0f Linyuan-7069 are just not So obvious as those of Jingdong-8．