Groundwater was studied for maize seed production in arid Northwest China. Different water and salt levels were tested. Saline water increased soil water content and salt levels. Less water and more salt decreased soil water and increased salt. Water with 3 g/L salt and 370 mm amount didn't reduce yield and improved water use efficiency. Irrigating with 370 mm water and salt below 3 g/L is recommended for this area. This study suggests a practical way to use saline water for irrigation in agriculture.