Sixteen maize cultivars widely planted in China were compared for their water-logging resistance and photosynthetic physiology under field conditions. The results showed that 1000-grain weight increased but the yield and grain number per spike reduced after water-logging. According to the relation between yield and relative injury rate in maize, 16 maize cultivars could be classified into 4 groups: group 1 with higher yield and high tolerance to water-logging, group 2 with lower yield and high tolerance to water-logging, group 3 with lower yield and low tolerance to water-logging and group 4 with higher yield and low tolerance to water-logging. The leaf weight, the root cap ratio and the leaf culm ratio can be used as the morphological indexes to measure the water-logging resistance in maize. The maize cultivars belonged to group 1 bloomed earlier no matter water-logging stress existed or not. The chlorophyll contents and the photosynthetic rates had no significant difference compared to the control in group 1 after 10 days water-logging, but they were significant higher than those of the other groups.