Abstract: Field experiment was conducted to study the effect of water and nitrogen on yield and nitrate content of amaranth (Amaranthus tricolour) and spinach (Spinacia oleracea) and their water use efficiency. The results showed that there were no significant differences in yield of amaranth and spinach with different nitrogen supply rate in soil under uniform water treatment, and no significant differences in different water treatment. But W1(traditional water treatment method ) was the lowest in water use efficiency. Nitrate content of amaranth and spinach was affected by supply nitrogen rate in soil mainly, the second was soil water content. So it is one of the effective method to decrease nitrogen supply rate in soil at the same time decreasing properly soil water content, in order to increase water use efficiency and vegetable quality.