Abstarct: Heat stress is one of the decreasing factors of rice yield. The aim of this experiment was presenting the probability of heat stress occurrence, and investigating the possibility of diminishing the harmful effects of heat stress on rice by ultrasonication and salicylic acid. The experiment was as Spielit Plot baxsed on randomizad complete block design with 3 replications carried out in Aliabad Katoul. Treatments were ultrasonication duration at four levels of control (no irradiation), 3, 6 and 9 minutes at a frequency of 42 kHz and foliar application of salicylic acid at three levels of control, spraying with concentration of one mM at 4-leaf stage, and spraying with concentration of of one mM at 4-leaf and flowering stages. The results indicated that rice faces heat stress. Generally, all traits including acticity of antioxidant enzymes ascorbate peroxidase and superoxide dismutase and rough rice yield were significantly affected by interaction of ultra sonication and salicylic acid.