This study evaluates effects of various weeds control methods and nitrogen fertilizer resources on density and dry weight of pigweed and the performance of corn forage as factorial in full random block design with 3 repetitions in research farm of Ferdowsi Mashhad University in 2014. The test treatments include weed control methods such as chemical control, compound (mechanical+ chemical) control, and no control and types of nitrogen fertilizer including (urea, sulfate ammonium, nitrate calcium, nitrate ammonium, and nonusing fertilizer). Density and dry weight of pigweed was measured four times in growing season to determine changes procedure. In the Corn primary stage, the performance of wet forage was also measured. The obtained results from test showed that forage performance at the end of growing season, and density and dry weight of pigweed after 60 days of planting were significantly influenced by control methods, type of nitrogen fertilizer, and interaction of control methods and type of nitrogen fertilizer. (P>0.01) the highest forage performance was obtained in compound control method and nitrate calcium fertilizer treatment with approximate weight of 12072kg/hec. 1205In no control and studied fertilizers treatment in test, the pigweed density has stayed constant with soft descending slope 20 days after planting so on, and its weight increased until 60 days of planting and then decreased until the growing season.