In order to evaluate the effect of potassium and zinc sulfate application on grain yield of maize (cv. KSC 704) under drought stress, an experiment was conducted as split factorial in randomized complete block design with three replications in Ilam, Iran during 2010-2011 growing season. Experimental factors consisted of irrigation (full irrigation, stop irrigation in flowering stage and stop irrigation in grain filling stage) were assigned as main plot, and potassium (0, 75 and 150 kg.[ha.sup.-1]) and for zinc (0, 30 and 60 kg.[ha.sup.-1]) were chosen as sub plot. The results showed that the irrigation affected most of characters. The highest grain yield was obtained from in full irrigation treatment. Potassium fertilizer had positive affect all studied traits except number of grain rows in ear. The Highest gain yield belonged to 75 kg.[ha.sup.-1]. 60 kg.[ha.sup.-1] zinc sulfate had the grain yield. The study showed that potassium and zinc sulfate can reduce negative effects of drought stress on grain yield and its components. Key words: Maize, Drought stress, Potassium, Zinc sulfate.