<span style="font-size:14px"><span style="font-family:Arial,Helvetica,sans-serif">Antioxidant defense system(s), pigments content and photosynthetic activity as well as some biochemical changes under drought stress were analyzed in maize (<em>Zea mays</em> L. cv. Giza 21) leaves to determine the response of &nbsp;plant to drought stress and to elucidate the role of various protective mechanisms against oxidative stress. It was found that the application of drought stress led to changes in the carbohydrates and protein contents. Total soluble sugars, accumulated in the leaves of water-stressed plants, whereas, starch and protein contents were dropped to a small amounts compared to the control. Furthermore, plants have well-developed defense systems againstreactive oxygen species (ROS), involving both limiting the formation of ROS as well asinstituting its removal. Within a cell, the activities of a range of antioxidant enzymes suchas superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase(APX) involved in scavenging ROS were investigated. During dehydrationthe SOD, APX and CAT increased significantly up to 4 days, then declined in their activities but still maintained higher than the control levels this indicates that the defense systems involvedare efficient in the protection of plant cells against oxidation. In addition, there was consistent increase in the lipid peroxidation and accumulation of malondialdehyde (MDA). The levels of hydrogen peroxide were also elevated during stressing periods. In this study we are reporting the negative response of maize plants toward drought stress especially on the antioxidant enzymatic activity for the prolonged drought effect.</span></span>