2,7-Dibromo-N-octylcarbazole (3) was synthesized from 4,4，-dibromobiphenyl by nitration, the Cadogan cyclization and N-alkylation. Nitration of 4,4，-dibromobiphenyl by HNO3 with n(4,4，-dibromobiphenyl)︰n(HNO3)=1.0︰4.0 gave 4,4，-dibromo-2-nitrobiphenyl (1) with a yield of 97% at 75 ℃ for 5 h. The cyclization of 1 by triphenylphosphine with n(4,4，-dibromo-2- nitrobiphenyl) : n(triphenylphosphine)=1.0 : 3.0 gave 2,7-dibromocarbazole (2) with a yield of 68% in Schlenk flask. N-alkylation of 2 by bromooctane with n(2,7-dibromocarbazole) : n(bromooctane)=1.0 : 1.5 gave the title product with a yield of 85% under the alkaline conditions. The structure of the product was characterized by IR, elementary analysis and 1H NMR spectra.