Six representative winter wheat cultivars released since 1949 in central Henan province were selected to study the effects of different water treatments on chlorophyll fluorescence characters and antioxidant enzyme activities in flag leaves during flowering and milky stages. The results showed that chlorophyll content index of winter wheat cultivars increased with years which set up the basis for improving the photosynthetic functions. Chlorophyll fluorescence parameters of winter cultivars bred in 1990s and after 1990s were higher than the early cultivars. The malondialdehyde content of the modern cultivars decreased and activities of superoxide dismutase increased more quickly after flowering stage, which showed stronger capacity of scavenging oxygen free radical. Peroxidase activities of the modern cultivars improved to resist droughts under drought stress. Activities of catalase and ascorbic acid peroxidase of the modern cultivars increased quickly to scavenge oxygen free radical which was helpful to the maintenance of stronger photosynthetic capability. 