A series of lithium or potassium hydrogen 1-(substituted phenoxyacetoxy)alkylphosphonates were designed and synthesized. All the title compounds were identified by IR, 1H NMR, and 31P NMR, some of them were further analyzed by MS and elemental analyses. The test for herbicidal activity indicated that most of the phosphonates (8) possessed excellent postemergence herbicidal activities against broadleaf weeds. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the fr...