SELECTING CULTURAL STRATEGIES FOR weed CONTROL SUCH AS INCREASING CROP DENSITY AND ALTERING PLANTING DATE ARE SOME IMPORTANT PARTS OF INTEGRATED weed MANAGEMENT. IN ORDER TO STUDY EFFECT OF DIFFERENT WHEAT DENSITY AND SOWING DATE ON weed DENSITY AND biomass AS WELL AS WHEAT YIELD, A FIELD STUDY WAS CONDUCTED IN 2007 AT RESEARCH FIELD OF AGRICULTURE COLLEGE OF SHIRVAN. THE EXPERIMENTS WERE ESTABLISHED AS A RANDOMIZED COMPLETE BLOCK DESIGN IN A FACTORIAL ARRANGEMENT OF TREATMENTS REPLICATED FOUR TIMES. TWO FACTORS INCLUDED WHEAT DENSITY (AT 400, 600, AND 800 PLANT M-2) AND SOWING DATE (ON OCTOBER 22, NOVEMBER 11, AND NOVEMBER 21). RESULTS SHOWED THAT GENERALLY RELATIVE DENSITY OF weedS (BROADLEAF AND GRASS) INCREASED AS SOWING DATE DELAYED, WHICH WAS DUE TO THE HIGHER GERMINATION AND EMERGENCE OF weedS. THE LEAST RELATIVE weed DENSITY WAS OBSERVED IN EARLY PLANTING TREATMENT (OCTOBER 22). GENERALLY, weed SHOOT biomass DECREASED SIGNIFICANTLY AS WHEAT DENSITY INCREASED. SOWING DATE HAD A SIGNIFICANT INFLUENCE ON BROADLEAF weed biomass AND TOTAL weed biomass. TOTAL weed biomass WAS HIGHER IN LATE SOWING DATE (NOVEMBER 21) THAN OTHER TWO SOWING DATE. INDEED, IN LATE PLANTED PLOTS, weedS HAD MORE OPPORTUNITY FOR GERMINATION AND GROWTH. ALSO, WHEAT SOWING DATE HAD A SIGNIFICANT INFLUENCE ON GRAIN YIELD. GRAIN YIELD WAS SIGNIFICANTLY LOWER IN LATE SOWING DATE (NOVEMBER 21) THAN THE OTHER SOWING DATES. FINAL WHEAT SHOOT biomass DECREASED SIGNIFICANTLY AS SOWING DATE DELAYED, SO THE LEAST biomass WAS OBTAINED IN LATEST SOWING DATE (NOVEMBER 21).