Abstract: Densities of the Russian wheat aphid (RWA)，Diuraphis noxia (Mordvilko)，and its natural enemies were surveyed at 5～10 day intervals in the summer of 1996 on spring wheat and wild hosts in Tacheng，Xinjiang Uygur Autonomous Region，China. The aphid was more abundant on spring wheat than on secale，Secale cereale L. and wild oat，Avena fatua L. and reached its peaks earlier on spring wheat and oat than on secale. Number of coccinellids in spring wheat field increased up to 516 per 100 tillers. The parasitized rates of D. noxia by Diaeretiella rapae and Aphelinus albipodus were up to 31.6% and 12.9% respectively. On the secale plants，42.9% of the aphids were parasitized by A. albipodus，and the predator Leucopis annulipes found as up to 16 larvae per 100 tillers. On the oat plants，62.3% and 31.8% of the aphids were parasitized by D. rapae and A.albipodus respectively. D. rapae and most coccinellids appeared in earlier stage of RWA infestation，whereas A. albipodus and L. annulipes occurred lately.

Key words: Russian wheat aphid(Diuraphis noxia (Mordvilko)), natural enemies, spring wheat, Secale cereale, Avena fatua