One field experiment was conducted in 2000/01 and 2001/02 winter seasons at the Agrittikural Expenments and Research Station, Faculty of Agriculture, Cairo University at Giza to study the competitiveness effect of grassy and broad leaf and total annual weeds under two seeding rates on wheat yield. A split plot design with four replications was used, where wheat seeding rates were distributed randomly in the main plots and weed interference treatments were allocated in the sub•iot. Weed interference treatments were weed free, broad leaf weeds, grassy weeds and total weeds competition. Wheat seeding rate of 100 kg/fed. increased wheat grain yield by 31.3 and 7.9% in 2000/01 and 2001/02 seesaw, respectively as compared to that obtained by the seeding rate of 70 kg/fed. Grassy broad leaf weeds and their total biomass were negatively correlated with wheat grain yield through the decline of number of grain per spike, number of spikes/m² and 1000•grain weight. Losses in terms of wheatagrain yield due to broad leaf, grassy and total weed biomass were 29.9, 41.1 and 54.3% in 2000/01 season and 27.3, 34.2 and 44.9% in 2001/02 season as compared to the weed free treatment Simple correlation matrix showed that the dry weight of total weeds, grassy weeds and broad leaf weeds bbmass were negatively correlated with wheat yield. Where correlation coefficients (r) were -0.820, •0.672 and -0.504, respectively over the two seasons. The yield was positively correlated with number of spikes/m² (0.9), 1030-grain weight (0.854), number of spikelets/spike (0/92) and weight of spike (0.504). This study showed that grassy weeds were more aggressive In their competitiveness effect than broad leaf weeds on wheat yield and its components. Thus, to Improve wheat productNity, the deOsion maker should take in consideration the weed type during planning strategy for weed control In wheat to prevent waed competition and minimize herbicidal application.