The effects of NaCl salinity and N on the growth, ion concentrations and photosynthesis (Pn) in three canola cultivars (‘SLM 046 ’ ‘Okapi’ and ‘Licord’) were investigated. The experiment was conducted with four NaCl levels (0, 50, 100, and 150 mM factoriallycombined with three N levels (100, 200, 300 mg l -1 ) as NH 4 NO 3 by adding to the half strength of Hoagland solution. The plants were growth in 121 pots filled with sand and perlite mixture (1:1) for 12 months. Salinity had a significant negative effect on all tratments, although the severity of the effect varied among the cultivars. High concentration of salinity (150 mM) decreased the leaf area by 63%, 68% and 76% in cvs ‘SLM 046 ’ and ‘Licord’ and ‘Okapi’ to that in control (Na 0 N 10 ). The plants growth were improved at 200 mg l -1 N concentration in cvs ‘Licord’ and ‘Okapi’, but it was reduced when the N concentration increased up to 300 mg l -1 . The growth of ‘SLM 046 ’ progressively increased with the increasing both salinity and N levels. Both Pn and transpiration rate were significantly reduced by the increase of salinity in all three cultivars. Increasing of N levels in the solution had no effect on Pn in various salinity levels in cvs ‘SLM 046 ’ and ‘Licord’, but in ‘Okapi’ cv. Pn decreased as N level increased. Salinity in the root zone led to a significant decrease in both K concentration and K/ Na ratio in the leaves in all cultivars regardless of the N levels. Within each N level, leaf Na concentration increased and K concentration decreased as salinity concentration in the root zone increased from 50 to 150 mM. Nitrate reductase (NR) activity in 150 mM treated plants decreased by 27%, 58% and 52% in cvs ‘SLM 046 ’and ‘Okapi’ respectively. The decreased activity of NR by the increased NaCl was accompanied by a decrease in total N and nitrate uptake. The deleterious effects of salinity on the plants growth appeared to be as the result of the reduction in Pn, K/Na ratio and NR activity in the salinity treated plants. It can be concluded that under salinity conditions increasing N concentration up to 200 mg l -1 in salt-sensitive cultivars to salinity is favorite in counteracting the adverse effects of salinity but thefurther increase of N concentration (300 mg l -1 ) may be ineffective or even harmful for the canola growth. In salt