In order to find high active pesticide, nine novel compounds of N-substituted ben-zoyl-N'-substituted arylthiourea were synthesized starting from industrial acifluorfen and its intermediate. Their structures were characterized by IR, ¹H NMR spectra and elemental analysis. The single crystal structure of compound 4b was determined by X-ray diffraction analysis. The crystal belongs to triclinic with space group P-1, a＝0.51588(19) nm, b＝1.0766(4) nm, c＝2.0596(8) nm, α＝81.113(6)°, β＝89.702(6)°, γ＝78.131(6)°, V＝1.1056(7) nm³, D_c＝1.445 Mg/m³, Z＝2, F(000)＝492, μ＝0.319 mm^－1. The preliminary biological tests showed that some of these title compounds have herbicidal activities.

Key words: 3-(2-chloro-4-trifluoromethylphenoxy)benzoic acid, acifluorfen, crystal structure, acylthiourea