IN ORDER TO ASSESS THE INTERACTION OF NITROGEN FERTILIZER UTILIZATION AND HERBICIDE DOSE ON COMPETITIVE ABILITY OF CORN AND WEEDS, AN EXPERIMENT WAS CONDUCTED IN FARS AGRICULTURAL RESEARCH CENTER (ZARGHAN) AS A SPLIT-FACTORIAL BASED ON COMPLETE RANDOMIZED BLOCK DESIGN IN 3 REPLICATIONS IN 2008.NITROGEN UTILIZATION WAS THE MAIN PLOT (BROADCASTING AND BAND METHOD) AND NITROGEN DOSE (300, 400 AND 500KG/HA) AND NICOSULFURON DOSE (0, 40, 60 AND 80G.AI./HA) WERE DISTRIBUTED AS SUB PLOTS, FACTORIALLY. THE RESULTS SHOWED THAT IN BROADCASTING METHOD, INCREASING OF WEED DENSITY WAS MORE THAN THE BAND ONE, BUT IN CORN THE REVERSE CONCLUSION WAS OBSERVED. IN HIGHER DOSES OF FERTILIZER AND HERBICIDE, CORN YIELD AND YIELD COMPONENTS INCREASED. OVERALL, 400KG/HA OF UREA+ 2LIT./HA NICOSULFURON WITH THE BROADCASTING METHOD IS BEST FOR CORN IN COMPETITION WITH WEEDS.