Abstract: The interaction effects of water stress and nitrogen fertilizer on sunflower variety "Shmas" were studied in pot cultivation. Urea as nitrogen fertilizer was applied and water stress was sporadically induced by a cycle of 10 day watering and 10 day stress period after 20, 30, 40 and 50 days of sowing. Node number and Root length were significantly affected by the interactive effect of water stress and nitrogen fertilizer dose. These two parameter will significantly decrease when either sporadic stress period is increased or urea dose is decreased. The nitrogen applied in three dose had effectively balanced the adverse effects of four sporadic stress periods.