Abstarct: The positive effect of using salicylic acid has been observed in many plants, but there is no consensus about the best time or the most suitable amount of this growth regulator. Therefore, in order to investigate the effect of salicylic acid on the growth and yield of barley cultivars, this research was conducted as a split-plot experiment in the form of a randomized complete block design with three replications in Bandar Turkmen city in the crop year of 1401-1400. In this research, the main factor of barley cultivars, including three barley cultivars (Auxin, Fardan and Sahra) and the secondary factor of salicylic acid application at three levels, including the control, was the application of one millimolar salicylic acid at the time of tillering and Ka at the time of stemming. According to the obtained results, it was found that there is a difference between cultivars in terms of measured traits (plant height, leaf area index, number of claws per plant, number of spikes per plant, number of seeds per spike, weight of 1000 seeds, biological yield, economic yield, index harvest, relative content of leaf water and leaf chlorophyll) there is a significant difference and the use of salicylic acid improved the measured traits. The results related to barley grain yield under foliar treatments showed that the highest grain yield in Aksin, Fardan and Sahra cultivars with an average of 4953.42, 4049.67 and 3346.87 kg per hectare, respectively, was related to foliar spraying at the tillering stage, which compared to no Foliar spraying in these cultivars showed an increase of 31.22, 18.23 and 7.83%, respectively. Also, the results showed that the use of salicylic acid foliar spray in the tillering and stemming stage caused an increase in other traits measured in different barley cultivars. In general, according to the changes of traits measured in barley cultivars in response to foliar spraying of salicylic acid at the tillering and stemming stages in order to complete the growth stages and achieve high yield potential, foliar spraying was more effective in Aksin and Fardan cultivars than foliar spraying at the tillering stage. Therefore, the application of one millimolar salicylic acid treatment during tillering and stemming can be used in order to increase yield and yield components of barley.