Field experiments were undertaken to evaluate the effectiveness of some chemical and biological insecticides against the spiny cotton bollworm Earias insulana (Boisd) and their impact on yield component of cotton, cultivar Lashata, at the location of the College of Agriculture /Abu-Ghraib during the growing season of 2010.Resulte indicated the superiority of the insecticide Cypermethrin in reducing losses in quantitative and qualitative characters of yield components of cotton, when used as one spray or two sprays during the growing season. The insecticide Comodor came the second in the effectiveness followed by Hostathion,the growth regulator Match and the biological insecticide Agreen respectively. When the insecticides where applied as one spray during bud formation stage, the percentages of yield losses in row cotton were,27.4, 30.2, 32.8, 35.3 and 37.6% respectively . However ,when these insecticides where applied for two times, the first one was at bud formation stage and the second was at the flowering and boll formation stage ,the percentages of yield losses were,15.4,18.2,19.6,21.5,and 24.3% for the mentioned insecticides respectively. According to the results of the present experiment ,the tested insecticides were varied in their effectiveness, however any of them could be used for controlling the pest ,taking in consideration the whole agro ecosystem, the timing of application and the growth stage of the host plant in order to ensure better control and environmental safety.