in Wiley InterScience (www.interscience.wiley.com).A series of novel 3-aryl-1-[2-(aryloxy)propanoyl]imidazolidine-2,4-diones were synthesized by the condensation of 3-aryl-imidazolidine-2,4-diones with 2-(aryloxy)propanoyl chlorides under mild conditions. Their structures were confirmed by IR, 1 H NMR, mass spectroscopy, and elemental analyses. The preliminary bioassay indicated that the target compounds II displayed excellent herbicidal activity against monocotyledonous (barnyard grass) and dicotyledonous (oil rape) plants.