The allelopathic effects of rice (Oryza sativa L.) varieties on weeds were studied. Results showed that the inhibitory effect of rice on the root growth of Echinochloa crus galli was higher than the effect on shoot growth. Zaojing 911 showed inhibitory effect on weed growth in laboratory and in field. The results showed that the inhibitory effect of rice on the root growth of Echinochloa crus galli was higher than the effect on shoot growth. Zaojing 911 showed inhibitory effect on weed growth in laboratory and in field.