A study was undertaken in the Department of Biochemistry, Bangladesh Agricultural University, Mymensingh to monitor the level of three selected pesticides at various dose levels. In this case edible part of red amaranth was extracted and analyzed for applied pesticide residues. It was found that after one day 0.0065 μg of cypermethrin retained per g of plant sample, which was 0.23% of the applied dose. While on the 3rd day of spray the level of residue was found to decrease (0.0024 μg g1-1) which accounted for 0.085% of the applied dose. In case of higher dose applied, the residue level of chlorpyrifos was 0.0173 μg g-1 whereas the level increased to 0.0237 μg g1-1 on 3rd day of application. It seemed that the uptake of chlorpyrifos by red amaranth from soil and its accumulation therein was higher on 3rd day of application. The residue level of carbofuran was very low both at 1st and 3rd day of application. However, an increasing trend of incorporation was observed on 3rd day of application. It is remarkable to note that when higher level of chlorpyrifos and carbofuran were jointly applied, the amount of chlorpyrifos as residue increased but the level of carbofuran decreased. Finally carbofuran could not be traced after 72 h of joint application. So study indicated that chlorpyrifos might exert antagonistic effect on the uptake/accumulation of carbofuran in plant system.