A　novel　synthesis　of　acridinium　ester　as　a　chemiluminescent　immunoassay　reagent　was　designed　in　this　paper.　This　novel　synthesis　involved　the　production　of　acridine-9-carboxylic　acid　from　diphenylamine,　the　acridine-9-carboxylic　acid　was　converted　to　acridine-9-carbonylchloride,　and　reacted　with　4-(2-N-succinimdyloxycarbonylethyl)　phenol,　to　produce　4-(2-succinimdy-loxycarbonylethyl)-phenyl-9-acridine　carboxylate,　this　is　followed　by　conversion　to　4-(2-succin-imdyloxycarbonylethyl)-phenyl-10-methylacridinum-9-carboxylate　fluorosulfonate(so　called　acridinium　ester).