Amiprophos-M,ethyl 2-nitro-4-methylphenyl N-isopropyl phosphoramido-thionate,oryatallizes in the triclinic space group P1 with two molecules in the unit cell.The crystallography parameters are.a=8.636 (1),b=10.483(2),c=10.694(2)Å;α=110.92 (1) °,β=111.27 (1) °,γ=8.97 (1) °; V=796.2 (3) ų; D_c=1.33 g/cm³;F (000)=336; (MoK_α)=3.2 cm^-1.The crystal structure has been solved by the direct method and refined by the block-diagonal least-squares procedures to final R values of R₁=0.055 and R₂=0.047.The phosphorns atom of the Amiprophos molecule forms four tetrahedral covalent bonds,of which the P-S bond ezhibits rather high double bond character.It implies that the empty 3d-orbital of the phosphorus atom should be involved in the chemical bond formation.