T HREE EXPERIMENTS were conducted at the Vegetable Experimental Farm ,Faculty of Agriculture ,Assiut University during two summer seasons 2015 and 2016 to study the effect of irrigation regime and salicylic acid foliar application on two cowpea cultivars .Each experiment subjected to one of three tested irrigation levels 50 ,70( and % 30 of the available water which equal soil moisture tension of 0.60 ,0.35 and 0.85 bar ,respectively .)Each experiment was laid out using strip plot arrangement in a randomized complete block design (RCBD )with three replications .Three salicylic levels 300 ,150 ,0( ppm )were randomized in horizontal plots while the two cowpea cultivars( Azmirly and Cream )7 were allocated in vertical plots .The results showed that the irrigation water deficit significantly decreased all the studied traits .Concerning salicylic acid( SA )application ,obtained data revealed that increasing the SA concentrations from( 0 control )to 300 ppm ,increased the plant ability to withstand drought .Also ,Azmirly cultivar was better than Cream 7 for all studied traits .The highest mean values of seed yield per hectar were obtained from Azmirly cultivar which was irrigated at70 %of the available water and sprayed with 300 ppm salicylic acid as foliar application .Protein patterns were analyzed in leaves of Azmirly and Cream 7 cultivars to study the changes in gene expression after one and two weeks of treatments with 150 ,0 and 300 ppm of salicylic acid( SA .)SA induced the expression of 11 new proteins as compared to the control treatment.