Abstract: According to typical method of saliferous soil washed by water in protected agriculture, the reduction of saline matter in soil and the water pollution load of nitrogen and phosphorus by runoff and leakage were studied with plot scale experiments and indoor soil column experiments. The results showed that 53%～64% of saline matter and 55%～60% of nitrate nitrogen were reduced, respectively, while 1.0～1.5 times of available phosphorus was increased in topsoil after saliferous soil was washed; the total water pollution loads of nitrogen and phosphorus by runoff and leakage were 7.66 kg/hm² of nitrate nitrogen, 0.77 kg/hm² of ammonium nitrogen, 12.71 kg/hm² of total nitrogen and 1.27 kg/hm² of total phosphorus, respectively.