In order to study the effects of drought stress on yield and agronomical characters of three plants in normal irrigation and drought stress, the experiment was doing with Split Plot based on Completely Randomized Block Design with four replications in Agricultural Research Station of Khoy in 1387. Irrigation was tested as the main factor in three levels: after 80, 120 and 160 (±5) mm evaporation of class A evaporation pan, and plant type as sub factor in three levels of millet (panicum miliacum cv. Notrifeed), sorghum (sorghum cv. Pagah) and corn (zea mays cv. Ksc 704). The results showed that there was significant difference between irrigation level, from the point of view of plant height, fresh and dry forage yield, and proteins percentage. The yield of fresh forage in irrigation level after 80, 160 (mm) after evaporation was average 97.7 and 80.2 tons ha-1 respectively Also, there is significantly difference between different plant levels from the point of view in all characters. Regarding the obtained results, the yield of fresh forage in corn and millet had maximum and minimum amount, respectively with the average of 103.9, 62.2 tons ha-1. There wasn't significant difference between interactive effects of irrigation levels and plant type in all characters.