Abstract:A study was conducted to investigate the effects of different concentrations of Mn, Zn and Fe on variations of ergot alkaloids contentin symbiont of Epichlo gansuensisAchnatherum inebrians. The results showed that: (1) The contents of ergine and ergonovine under Mn2+ 5.0 mmol·L-1 had a peak value at the 3rd week,which had significant(P<0.05) difference with other Mn2+ treatments, but the contents of ergonovine under 0.01 mmol·L-1 had a peak value at the 6th and 9th week. (2) The contents of ergine had maximum under Zn2+ 7.0 mmol·L-1 at the 3rd , 6th and 9th week , and the contents of ergine was significantly (P<0.05) higher at the 3rd week than those at the 6th and 9th week. (3) The contents of ergonovine had maximum under Fe2+ 21.0 mmol·L-1 at the 3rd, 6th and 9th week. The contents of ergine had a peak value under 6.0~12.0 mmol·L-1 at the 3rd, 6th and 9th week , and the contents of ergine was significantly (P<0.05) higher at the 3rd week than those at the 6th and 9th week. The contents of ergonovine had maximum under Fe2+ 0.0 mmol·L-1 at 3rd and 6th week, but under 0.03 mmol·L-1 had a peak value at 9th week. So,high concentrations of Mn, Zn and Fe elements is helpful to stimulate the drunken horse grass infected by endophytic fungi to accumulate tow ergot alkaloid for a short time treatment.