Abstract: Aqueous extracts of Artemisia frigida leaf and stem and soils beneath A. frigida  were used to test their allelopathic effects on the seed germination and seedling growth of three Poaceae plants (Leymus chinensis, Stipa krylovii, and Cleistogenes squarrosa) on Leymus chinensis grassland. The aqueousextracts of A. frigida leaf and stem decreased the seed germination index of testplants and prolonged their seed germination time, and inhibited the shoot growth of the three plants and the root growth of S. krylovii. The aqueous extracts at concentration ≥0.075 g·ml^-1 presented a strong inhibition on the root growth of L. chinensis, while those at concentration ≤0.05 g·ml^-1 had less effects. For the root growth of C. squarrosa, the aqueous extracts showed a “low-promotion and high-inhibition effect”. Under the effectsof A. frigida soil, the seedling growth of test plants was inhibited. The sensitivity of test plants to the allelopathic effects of A. frigida was in the order of S. krylovii＞L. chinense＞C. squarrosa, with a higher sensitivity of root growth than shoot growth.

Key words: Artemisia frigida, inhibition effect, test plants, Leymus chinensis grassland, red soil, vegetation type, pH, exchangeable acidity, profile distribution.