Abstract: The effects of drought stress on cotton seedlings were evaluated in terms of the activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and the content of malondialdehyde (MDA). Similarly, the effects of foliar application of glycine betaine (GB) in plants subjected to drought were examined. The contents of compatible solutes, proline, and soluble sugars were measured to assess the osmotic adjustments under different treatments. The levels of SOD, POD and compatible solutes are increased under drought stress and this effect is, in general, enhanced by the treatment with GB. In the presence of exogenous GB, there is a diminution in the drought-induced increase in the content of MDA. The activity of CAT was not affected by drought stress and GB. This shows that the low concentration of GB alleviates the damage of cotton seedlings caused by drought stress.