Abstarct: This study investigates the effect of deficit irrigation stress and foliar application of different calcium sources on growth, seed yield, and some quality traits of single cross 704 corn implementing a split-plot experiment at Shahrood University of Technology through a completely randomized block design with two factors and 3 experimental replications in the cropping year of 2019-2019. Experimental treatments include deficit irrigation at three levels of 8 (control), 12 and 16 days of irrigation intervals as the main factor and treatment of calcium sources including control, calcium chloride in two concentrations of 1.5 and 3 kg per thousand liters of water and calcium silicate in two concentrations of 1.5 and 3 kg per thousand liters of water were considered as sub-treatments. The results showed that the interaction of deficit irrigation and calcium treatment had a significant effect on traits such as seed yield, the components of seed yield (1000-seed weight and number of seeds per plant), relative leaf water content, chlorophyll A, electrolyte leakage, proline and carbohydrate levels. With increasing irrigation level from 8 to 16 days of irrigation intervals, seed yield and the components of seed yield decreased, but the use of calcium had a significant effect on corn seed yield and the components of seed yield, and also increased them even at drought level. So that the application of calcium increased the number of seeds per plant by 30% compared to the control treatment and the weight of 1000 seeds increased significantly with the application of calcium. The highest corn seed yield was observed in the treatments of calcium chloride 1.5 and 3 kg per thousand liters of water and calcium silicate which were not statistically significant. The lowest seed yield was 3696 kg per hectare ha in 16 days of irrigation and no calcium application. Irrigation treatment increased the amount of proline and soluble carbohydrates in the leaves and also increased the leakage of electrolytes and decreased the amount of chlorophyll and the amount of relative humidity in the leaf tissue. However, the use of calcium to some extent prevented the negative effect of deficit irrigation stress on these traits, especially on land, but the use of 3 kg per thousand liters of calcium silicate water had a greater effect on these traits. In general, it can be noted that the application of calcium can have a positive effect on the morphological and physiological characteristics of corn under drought stress (deficit irrigation), which ultimately improves seed yield by improving seed yield components and physiological traits. According to the results of this experiment, the application of 3 kg per thousand liters of calcium silicate water was more appropriate than other experimental treatments.