The field experiment was carried out in three locations at North Sinia Governorate, Egypt, during two successive summer seasons 2018 and 2019, to study the Effect of the three saline water levels (3.14, 6.25 and 9.37 dSm-1) treated with or without magnetic field on some soil chemical properties and cowpea productivity and quality. In both seasons, each experiment was conducted in a randomized complete blocks design (RCBD) with six replicates. The obtained results showed that using irrigation water with high salinity levels decreased salinity of soil and soil pH for irrigation water treated with magnetic compared with untreated. Available macro and micronutrients in soil as affected with magnetic irrigation water were higher than untreated water. Growth parameters, yield components (number of pods and weight of pods and seed yield fed-1) and some chemical constituents (macro-micronutrients in shoot and seeds contents, total chlorophyll content, proline, protein and carbohydrates) were higher with magnetic treated irrigation water as compared to control. Magnetized Irrigation water salinity of 3.14 and 6.25 dSm-1 effects with magnetic water were higher than untreated showed a uniform impact in soil properties and cowpea growth inhibition and its productivity under high salinity stress condition. The use of magnetized water has a role in reducing EC as there has been a decrease in the value of EC compared to un-magnetized water at Galbana, Romana and Rabaa), respectively. Using irrigation water salinity treated with magnetic to soil increased of leaching soluble salts.