Cyclocarya paliurus seedlings were cultured in a greenhouse under saline conditions in 50 L black plastic boxes containing Hoagland-Arnon nutrient solution. Plants were treated with a nutrient solution plus 85 mM NaCl and 0, 6, 12 or 18 mM Ca(NO₃)₂. Vegetative growth, leaf and root Na⁺ and Ca²⁺ concentrations were measured. Na⁺ toxicity symptoms were observed in plants non-treated with Ca²⁺. Shoot length was higher in Ca²⁺ treated plants, although shoot growth was reduced at 18 mM CaNO₃, probably due to the high total ion concentration reached in the external solution. Ca²⁺ supply linearly increased leaf and root Ca²⁺concentration and decreased leaf Na⁺ concentration. However, there were no differences in root Na⁺concentration. Results indicate that Ca²⁺ may take part in the Na⁺ exclusion mechanism, mainly preventing Na⁺ transport to the shoot that may be an important ability for survival under saline conditions.

Key words: Cyclocarya paliurus, NaCl, sodium exclusion, calcium.