A supervised field trial on rice was conducted at the experimental farm, BCKV, West Bengal where the mixture formulation of bispyribac sodium 4% + metamifop 10% was applied at 14 days after transplanting of the rice seedlings at three doses viz. recommended dose i.e. @ 70 g a.i. ha-1 and double dose i.e. @ 140 g a.i. ha-1and another is untreated control The residue was extracted by QuEChERS method and quantified by liquid chromatography electrospray ionization tandem mass spectrometry. The limit of quantification of both the compound was 0.02mg kg-1in all the substrates (rice green plant, straw, grain, husk, and soil).The half-life (T1/2) value of Bbispyribac sodium in soil ranged from 17.71 -23.16 days where as the T1/2 value of metamifop in soil and rice green plant ranged from 12.54 - 15.84 and 1.91-2.71 days respectively. No residue of bispyribac sodium and metamifop was quantified in harvested rice straw, grain, husk and soil.