his article has studied the ecological effect of new pesticite monocarboxoldehyde(DMAH)to the plant-soil system,The results show that the siw treated concentrations(CK.25%.DMAH diluted by 1500,1000,800.500,100 times)have different degress of preventionand control effect to cotton insect pest. The 100 times dilution is the best. which can preventmany kinds of cotton insect pest.DMAH has no bad effect on structure and function of thecotton population.The high concentraction DMAH(800 times to 500 times)can mak...