The efficiency of mulching to reduce soil surface evaporation depends on the climate and the characteristics of the different mulching materials. This study aims to investigate the effect of varying mulching materials on soil evaporation, total chlorophyll, growth parameters, leaf area, yield, N, P, and K content in straw and seeds, and water use efficiency of cowpea plants (Vigna unguiculata L.) variety Karim-7 under two soil types with different texture as well as the interaction between them. For this, the pot experiment during the summer of 2021 was conducted at the Soils and Water Department farm, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt. Two types of soil were used: clay and loamy sand. The mulching materials used for the soil's surface were black plastic (T2), white plastic (T3), rice straw 3 (T4), 6 (T5) and 9 cm thickness (T6), gravel 3 (T7), 6 (T8) and 9 cm thickness (T9), in addition to the control treatment (T1: without mulching). In general, mulching materials reduced water consumptive use (CU), enhanced growth parameters, and increased the yield of cowpea compared to the control. As a result, using these materials is recommended to prevent water losses by evaporation, conserve soil moisture, and increase the water use efficiency (WUE) of cowpea plants.