This work aimed at assessing water stress on two varieties of maize during its phenophase in Guinean cli- mate zone of Benin Republic. For this purpose, two maize varieties seeds were considered «EDOUGOTIN» and «QPM» and planted on 25th August in pot experiment. Experiment is carried out in a screen-house at the Research Station of International Institute of Tropical Agriculture (IITA/Benin) in Abomey-Calavi. Pots were filled with 10kg of the soil each and were arranged in completely randomized design as a 4×5×3 factorial experiment. Water stress at four phenological stage was applied on two varieties. Each of the treatments experienced a 10 days' dry spell at their respective phenological stages but the No water stress experienced a total of 0 day. Significant difference was observed in growth parameters among the treatments (p<0.05). It was discovered that water stress was not affected parameters of the two varieties in the same way during different phenology stage. The most sensitive stage of maize to water stress are reproductive and grain filling stage.
