Suaeda salsa L. can grow in the intertidal zone, or on inland saline soils. After pretreatment with different concentrations of nitrogen (0.3 and 5 mmol/L NO₃^--N), seedlings of two S. salsa populations were watered with a nitrogen-free nutrient solution (nitrogen starvation) at 200 mmol/L NaCl. After one or two weeks, the chlorophyll content and NO₃^-, nitrate reductase (NR) activity, photosynthetic oxygen evolution rate in leaves, and shoot and root dry weight were measured. With 0.3 or 5 mmol/L NO₃^--N pretreatment, the NO₃^- content in leaves from the intertidal population was higher than from the inland population throughout the whole study. Nitrogen starvation decreased the chlorophyll content, NR activity, and photosynthetic oxygen evolution rate in leaves from the inland population more severely than in the intertidal population leaves. This was especially apparent when seedlings were pretreated with 0.3 mmol/L NO₃^--N. As for S. salsa from inland saline soils, the root/shoot ratio decreased significantly after nitrogen starvation. However, nitrogen starvation had no adverse effects on this ratio for the intertidal population after the pretreatment. The results suggest that S. salsa from the intertidal zone has a higher capacity for NO₃^- storage and nitrogen assimilation under low nitrogen conditions. As a result, the intertidal population seedlings have a higher ability for NO₃^--N reutilization to maintain nitrogen metabolism and normal photosynthesis. This indicates that S. salsa from the intertidal zone can better adapt to low nitrogen habitats as compared to the inland population. These traits may affect the distribution of S. salsa in their natural saline environments.