Abstract: Allelopathic rice cultivar “PI312777” and non-allelopathic rice cultivar “Lemont” were used to explore physiological and biochemical response of rice cultivars with different allelopathic potentials to drought and weed stresses in paddy fields. The results indicated that under double stress (drought and weed), the order of biomass was “PI312777” in dry field > “Lemont” in wet field ≥ “PI312777” in wet field > “Lemont” in dry field. Further analysis showed that under dry field condition, “PI312777” rice exhibited the highest leaf chlorophyll content, protective enzymes activities, net photosynthetic rate and water use efficiency, but the lowest transpiration rate. Under dry conditions, “Lemont” rice exhibited the lowest leaf net photosynthetic rate, protective enzymes activities, soluble sugar content, soluble protein content and water use efficiency, but the highest MDA content. These results suggested that allelopathic rice “PI312777” had better adaptability and endurance to water deficiency than non-allelopathic rice “Lemont”.