Abstract: UV spectrometry measurement on the indole alkaloids (IA) contents of seven wheat varieties (KOK1679,My295,Li,Han4564 and Yanda1817,resistant to S. avenae;Shaanximazha and Lovrin10,susceptible to S. avenae) showed that during tillering and stem elongation stages,KOK1679,My295 and Li had a higher IA content (>0.5 mg穏^-1 FW);and during heading and anthesis stages,the penultimate leaves of all five resistant varieties contained higher IA (>0.5 mg穏^-1 FW).The IA content was lower in the flag leaves of both resistant and susceptible varieties,but was significantly higher in the ears of resistant varieties (up to 0.645 mg穏^-1 FW in KOK1679) than in those of susceptible ones.It was showed that the IA content in wheat's ear played an important role in the resistance to S.avenae.