Abstract: A three years experiment was carried out to investigate the effects of saline water and soil matric potential (SMP) on tomato water use, water use efficiency (WUE) and soil salinity under drip irrigation in semi-humid regions of North China. The results indicate that tomato seasonal water use dec with the increasing of electrical conductivity of saline water (ECi), and decreased with the decreasing of SMP. Water use efficiency increased a little with the increasing of ECi, and increased with the decreasing of SMP. After three-year saline water irrigation, the soil salinity in the layer of 0～90 cm did not increase obviously.