Maize is a major crop in Iran and its grain yield can be severely reduced by weeds competition. Integrated weed management is the best way to control the weed that helps minimize herbicide application rate and resistance, and costs for weed control. Therefore, in order to study the effect of planting patterns and herbicides combination on corn yield and weeds of fields corn ( Zea mays L.); under competition conditions, an experiment was conducted in 2007 at research field of Department of Weed Research, Plant Protection Research Institute, Tehran, using split plot design with 4 replications. Experimental factors were corn planting patterns in 4 different types (one row planting on each ridge with 74,000 plants ha -1 and two rows planting on each ridge with 74,000, 92,500 and 111,000 plants ha -1 ) in main plot and 5 combinations of herbicides (1- atrazin 1L/ha plus EPTC 4L/ha, 2- atrazin 1L/ha plus EPTC 5L/ha, 3- atrazin 1L/ha plus EPTC 6L/ha, 4- atrazin 1L/ha plus allachlor 5L/ha, 5- EPTC 6L/ha) in subplot. Control plots were consist of complete hand weeding and none-sprayed. Sampling was implemented every two weeks from 0.225-squere meter surface. Measured factors consisted of height, leaf area and dry matter of corn and quantity, kind and dry matter for weeds. In final sampling yield and component yield calculated and reported. Results showed that under all planting patterns the complete hand weeding control plots had the highest amount of leaf area index, crop growth rate, leaf area ratio, net assimilation rate, relative growth rate, total dry matter, yield, hundred kernal weight, number of rows on an ear and number of kernal per row. But, it had the lowest plant height. Two rows planting on each ridge with 92,500 plants ha -1 reduced herbicide consumption because in this pattern there was no significant different between reduced doze and normal doze. Weeds population and biomass percentage reduction were the highest in two rows planting on each ridge with 92,500 plants ha -1 that caused the highest yield in this pattern. In addition, two rows planting on each ridge with 92,500 plants ha -1 had highest leaf area index, leaf area ratio, crop growth rate, net assimilation rate, relative growth rate and total dry matter. Herbicides combination also had no significant effect on yield, thought EPTC 6L/ha had highest hundred kernal weight and second lowest plant height after hand weeding control plots. There were no significant different between one row planting on each ridge with 74,000 plants ha -1 and two rows planting on each ridge with 111,000 plants ha -1 on yield, but i two rows planting on each ridge with 74,000 plants ha -1 , atrazin 1L/ha plus EPTC 4 and 5 L/ha with 7394.14 and 7499.77 kg