Abstract: Rice may suffer serious water stress during its growth period. Drought affects the process of physiology metabolizability. Ten rice and upland rice varieties with different drought resistant abilities were used as experimental materials. Changes in ascorbic acid (Vc)content, free amino acid content, soluble protein content ,malondialdehyde (MDA)content and antioxidative enzyme activities were studied under both irrigation and drought conditions at flowering stage. The results were as follows: water stress increased Vc content, free amino acid content, soluble protein content and malondialdehyde (MDA)content, and increased superoxide dismutase(SOD), catalase (CAT) and peroxidase (POD) activities in leaves at flowering stage. Correlation analysis showed that drought-resistant coefficient significantly correlated or very significantly correlated with relative value of Vc content, free amino acid content, MDA content and SOD activity under both irrigation and drought conditions, therefore, relative value of thesecould be selected to using the identification indexes of drought resistance at flowering stage. Using stepwise regression equation to evaluate the drought resistance of rice cultivars was more scientifically and reliably.