Satureja khuzistanica Jamzad is an endemic medicinal plant which grows naturally in arid rangelands of south west of Iran. It is also being cultivated in arid regions with salt problems. So,it is necessary to find a method to develop its cultivation under salinity condition. This study was aimed to determine effects of 24-epibrassinolide(EBL) in three levels (0,1and2µM) on reduction of negative effects of salinity on morpho-physiological and biochemical traits in S. khuzistanica plant under four salt levels(0,3,6,9 ds/m). A pot experiment was conducted using factorial experiment based on a completely randomized design with three replications in greenhouse at Shahid Bahonar University ofKerman,Iran in2021. The results of ANOVA showed that values of all morphological traits, including stem and root lengths, fresh and dry weights of aerial parts significantly reduced with increasing salt concentration(p<0.01). The results showed that application of1 and 2µMEBL had better performance at all salt levels. The amounts of total chlorophyll,N,P+,K+andK+/Na+had significantly reduced by increasing the salt concentration alone and combined with EBL. The highest amounts of the latter traits were observed at 2µMEBL without salt. The amounts of anthocyanin,proline,sugar and Na+,significantly increased by rising salt levels. The highest amounts of anthocyanin with values of 38.64and 38.21mg/g,were obtained at9ds/m salt coupled with2and1µMEBL, respectively. The lower amount ofNa was observed under 2µMEBL. The highest sugar value(2.02mg/g) was observed in 9 ds/m salt coupled with 2µMEBL. Similarly, for proline content, the highest values of 0.315and 0.312mg/g were obtained in9ds/m salt coupled with 1and2µMEBL, respectively. There was no significant difference between 1and2µMEBL levels in terms ofroline. Overall, 2µMEBL was the best treatment to alleviate the negative effects of salt at all treatments. According to our findings, 24-epibrassinolide application at appropriate dose, as an environmentally friendly strategy, can be useful to improve S.khuzistanica tolerance and its production in arid rangelands with salt problems. تفاصيل المقالة