TO EVALUATE THE INTERACTION OF NITROGEN RATES AND NICOSOLFORUN DOSES, A FACTORIAL EXPERIMENT DESIGN WAS CONDUCTED BASED ON RANDOMIZED COMPLETE BLOCK DESIGN WITH THREE REPLICATIONS AT RESEARCH FIELDS OF UNIVERSITY OF TEHRAN IN 2007. NITROGEN FOUR LEVELS WERE (0, 180, 270 AND 360 KG/ HA) AND NICOSOLFURON HERBICIDE VIA FIVE DOSES (0, 20, 40, 60 AND 80 G AI / HA) WERE CONSIDERED. THE RESULT ILLUSTRATED, EXCEPT RUSSIAN KNAP WEED IN THE HIGHEST AMOUNT OF NITROGEN (I.E 360 KG/HA) THE OTHER WEED SPICES SHOWED A POSITIVE REACTION TO THE HIGH LEVEL OF NITROGEN FERTILIZER TREATMENTS. THE BEST TREATMENTS WERE HERBICIDE DOSES WITH 60 AND 80 G AI /HA AND NITROGEN FERTILIZER IN BOTH 180 AND 270 KG/HA, RESPECTIVELY. THE MORE NITROGEN FERTILIZER USED 360 KG/HA, THE MORE HERBICIDE DOSES NEEDED, TO EFFECTIVE CONTROL OF EARLY WEED. BECAUSE, WEED COULD GROW BETTER BY REALIZING OF MORE RESOURCE.