The　electrochemiluminescence　(ECL)　behaviour　of　a　new　reagent　10,10＇-dimethyl-3,3＇-disulfo-9,9＇-biacridine　(DMDSBA)　was　studied.　The　effects　of　the　electrochemical　parameters,　the　reaction　medium　and　pH　on　the　ECL　were　investigated　in　detail.　It　was　found　that　the　new　reagent　DMDSBA　gave　a　strong　electrochemiluminescence　in　KNO3　solution　when　an　appropriate　voltage　was　applied　on　glassy　carbon　electrode.　Under　the　optimum　conditions,　the　natural　logarithm　of　the　ECL　intensity　of　DMDSBA　has　a　good　linear　relationship　with　the　natural　logarithm　of　the　concentration　of　DMDSBA　in　the　range　of　1.0×10-5-1.0×10-8　mol·　L-1,　the　detection　limit　of　DMDSBA　was　2.3×10-9　mol·　L　-1.　The　cyclic　voltammetry,　fluorescence　spetrum　and　ECL　spetrum　for　this　ECL　system　have　also　been　investigated　in　detail,　based　on　which　a　possible　mechanism　for　the　ECL　of　DMDSBA　was　proposed.　©　Editorial　office　of　Acta　Physico-Chimica　Sinica.