A two-factor randomized experiment was conducted to investigate the effects of water stress on microbial abundance，diversity，community structure and enzyme(sucrase，urease，alkaline phosphatase and dehydrogenase)activities in the rhizosphere soils of two cultivars maize in three periods(flare opening，filling and maturity).Four treatments were set up，that is，two maize cultivars(“Zhengdan 958” and “Nonghua 101”)were planted under water stress and normal water supply，respectively.The results showed that water stress significantly inhibited the abundance of gram-negative bacteria and arbuscular mycorrhizal fungi in rhizosphere soils in three periods and the abundance of common bacteria and gram-positive bacteria in maturity period..The evenness index of microbe increased and the community structure changed obviously under water stress.Under water stress，dehydrogenase activity in filling period and the activities of alkaline phosphatase and dehydrogenase in maturity period significantly decreased，and sucrase activity in maturity period significantly increased..The abundance of arbuscular mycorrhizal fungi and dehydrogenase activity in the rhizosphere soil of “Nonghua 101” were higher than that of “Zhengdan 958”，but the diversity and evenness of microorganisms were lower in filling period.The interaction of water and cultivar only had significant effects on the abundance of actinomyces in filling period and that of arbuscular mycorrhizal fungi in filling and maturity periods and microbial community structure in three periods..