A　novel　chemiluminescence　immunoassay　(CLIA)　of　total　thyroxin　(TT4)　with　the　acridinium　ester　of　DMAE　center　dot　NHS　[2＇,6＇-dimethyl-4＇-(n-succinimidyloxycarbonyl)　phenyl-10-methyl-acridinium-9-carboxylate　methosulfate]　labeled　has　been　developed.　In　our　method,　microwells　were　coated　with　anti-T4　monoclonal　antibody　(McAb)　and　DMAE　center　dot　NHS　synthesized　by　our　laboratory　was　conjugated　with　streptavidin　(SA).　T4-BSA　was　conjugated　with　biotin-N-hydroxysuccinimide　(B　center　dot　NHS),　T4-BSA-　B　center　dot　NHS　and　the　T4　in　the　standard　or　sample　competitively　react　with　anti-T4　McAb.　Streptavidin-biotin　separation　and　enhanced　techniques　were　applied　in　this　assay.　The　presented　approach　shows　many　excellent　characteristics,　particularly,　rapid　assay　process　and　high　detection　sensitivity.