Abstract: Four varieties of annual Hydrangea,included ‘Blue Lover’‘Endless Summer’ ‘Blue Butterfly’ and ‘Camilla Powder’,were used as experimental materials, the plants were subjected to continuous drought stress using the natural water loss method for 0,5,10,15 days, the effects of drought stress on the leaf anatomical structure and physiological characteristics of Hydrangeawere studied, in order to provide reference for the introduction and expansion of Hydrangea in the northwest region of China.The results showed that drought stress led to a decrease in the RWC of Hydrangea leaves.POD activity decreased first and then increased, while CAT activity increased first and then decreased.MDA content and SS content both increased with the severity of drought stress.The greater the leaf thickness, upper epidermis thickness, media thickness, palisade tissue thickness, sponge tissue thickness, and palisade tissue thickness/sponge tissue thickness ratio, the stronger the drought resistance of Hydrangea.The comprehensive evaluation of drought resistance for the four varieties using the membership function method was as follows, ‘Camilla Powder’＞‘Blue Butterfly’＞‘Endless Summer’＞‘Blue Lover’.