The laboratory test showed that Lycoris radiate water extract had a stronger inhibitory effect on the seed germination and seedling growth of radish, cucumber, tomato and rape. After treated with 0.0125 g x ml(-1) of the extract, tomato seed could not germinate, but the seed germination inhibition rate of rape, radish and cucumber was only 17.73%, 14.97% and 2.65%, respectively. Under the same concentrations of the extract, sprout growth was inhibited more strongly than root growth. L. radiate methanol extract could inhibit the sprout and root growth of endosperm-removed wheat and sorghum, and the effect was stronger for sorghum than for wheat. All of these illustrated that L. radiate extracts mainly inhibited non-photosynthesis activity, but could also inhibit photosynthesis activity to some degree.