Allelopathy of 0(control treatment),0.1,0.2 and 0.5 g/mL methanol extracts and aqueous extracts of rhizosphere soil from Stipa bungeana were studied using the seeds of S.bungeana,its dominant species Stipa grandis and Thymus mongolicus as receivers and by laboratory bioassay methods.Compared with the control,the results showed that:(1)Methanol extracts inhibited the germination of S.bungeana,Stipa grandis.Aqueous extracts stimulated the germination of S.bungeana,and it stimulated the germination of T.mongolicus partialy,but inhibited that of S.grandis.(2)Methanol extracts had different effects on different receivers,it barely affected the growth of root and shoot of S.bungeana and S.grandis,but inhibited the growth of T.mongolicus significantly.Aqueous extracts could not stimulate the root growth of S.bungeana,the same to the root and shoot growth of the other receivers,but had significant stimulation to the shoot growth of S.bungeana.(3)Methanol extracts inhibited the growth of T.mongolicus and S.grandis,it stimulated the growth of S.bungeana except the concentration of 0.2 g/mL.Aqueous extracts stimulated the growth of S.bungeana and T.mongolicus,but inhibited that of S.grandis.Therefore,methanol extracts and aqueous extracts of rhizosphere soil from S.bungeana are different,and they have different effects on different receivers.one receiver has different reaction to different extracts.