Abstract: To study the impact of autumn low temperature of Jiangxi province on rice leaf physiological characteristics and yield function during the flowering stage，five artificial environmental control experiments and one basis experiment were designed in artificial climate chamber in Nanjing University of Information Science ＆ Technology from August to October in 2013.The processing time of control experiments were 3d，6d，9d，12d and 15d（denoted as T3d，T6d，T9d，T12d and T15d），respectively，with test temperature of 22℃/17℃（day/night），and the basis experiment was set at 25℃.The results showed that，（1）peroxidase（POD），superoxide dismutase（SOD）and catalase（CAT）activity and malondialdehyde （MDA）content gradually increased with prolonged low temperature，and cells would suffer serious damage after 15d of low temperature processing.（2）Compared with CK，the maximum photosynthetic rate and maximum carboxylation rate of T15d fell by 65.99% and 67.44%，respectively，at the same time the blade photochemical quenching（qP），maximal photochemical efficiency（Fv/Fm）and photoelectronic transfer rate（ETR）also reduced by 19.50%，10.25% and 42.77%，rather than the photochemical quenching（qN）increased slightly.（3）Underthe influence of low temperature，photosynthetic pigment synthesis had been restrained，so the chlorophyll a，chlorophyll b and carotenoid content decreased significantly.（4）With low temperature treatment during flowering period，ear length，effective tillers，seed setting rate and grain weight etc significantly were much lower than CK，which resulted in a significant decline in production，and T15d declined up to 48.42% as example.Therefore，autumn low temperature of late rice at flowering stage could obviously inhibit the function of physiological activity of rice leaf，which leaded to a significant reduction in the production，and the results of this study would provide a scientific basis for early warning and disaster assessment of autumn low temperature.

Key words: Late rice, Flowering stage, Autumn low temperature, Photosynthesis, Yield