To maintain high wheat grain yield in areas where frequent and periodic waterlogging occurs,the effects of waterlogging on the photosynthesis,growth,yield,and protein content of three wheat cultivars,namely Xiangmai55(X55),Jingmai102(J102),and Zhengmai9023(Z9023),in four different growth stages were investigated.Experiments were conducted in specially designed experimental tanks in the middle and lower reaches of the Yangtze River during the 2012-2013 and 2013-2014 wheat growing seasons in China.Results showed that X55 was the most susceptible to waterlogging,followed by J102 and Z9023.Chlorophyll content reduction and leaf senescence,which resulted in decreased green-to-total leaf number ratio,were induced to the greatest extents by waterlogging in booting and flowering stages,followed by milky stage.Meanwhile,chlorophyll content in flag leaf,plant height were significantly decreased by waterlogging in jointing stage but effectively recovered after waterlogging withdrawal,and recovery ability varied among the cultivars.Plant biomass and grain yield were most significantly decreased by waterlogging in booting and flowering stages,followed by milky and jointing stages.Grain protein content was also considerably affected by waterlogging depending on growth stage and cultivars.The decreased grain yield caused by waterlogging was mostly due to the sharp decline in 1 000-grain mass.Waterlogging led to reduced protein yield in all growth stages in three wheat cultivars.Above all,in this experiment,waterlogging decreased grain yield significantly,and waterlogging at booting stage and flowering stage was most serious.Comparing the three cultivars,X55 was most sensitive to waterlogging. To maintain high wheat grain yield in areas where frequent and periodic waterlogging occurs, the effects of waterlogging on the photosynthesis, growth, yield, and protein content of three wheat cultivars, namely Xiangmai 55 (X55), Jingmai 102 (J102), and Zhengmai 9023 (Z9023 Experiments showed that X55 was the most susceptible to waterlogging, followed by J102 and Z9023. Chlorophyll content reduction and leaf senescence, which resulted in decreased green-to-total leaf number ratio, were induced to the greatest extents by waterlogging in booting and flowering stages, followed by milky stage. , chlorophyll content in flag leaf, plant height were significantly decreased by waterlogging in jointing stage but effectively recovered after waterlogging withdrawal, and recovery ability varied among the cultivars. Plant biomass and grain yield were most significantly decreased by waterlogging in booting and flowering stages, followed by milky and jointing stages. Protein content was also significantly affected by waterlogging depending on growth stage and cultivars. decreased bean yield caused by waterlogging was mostly due to the sharp decline in 1000-grain mass. Waterlogging led to reduced protein yield in all growth stages in three wheat cultivars. Abbove all, in this experiment, waterlogging decreased grain yield significantly, and waterlogging at booting stage and flowering stage was most serious. Comparing the three cultivars, X55 was most sensitive to waterlogging.