Abstract: After the sample was extracted with ethanol, the extract was injected to the capillary for capillary electrophoresis (CE) separation by electric sampling for 10 s with the injection voltage of 10 kV. The running buffer solution for CE was 10 mmol·L^-1 PBS (pH 5.13) and the separation voltage was 15 kV. The dendrobine after CE separation reacted with 5 mmol·L^-1 Ru(bpy)₃²⁺ solution (in 70 mmol·L^-1 PBS with pH 8.10) in electrochemiluminescence (ECL) detection cell, resulting the ECL intensity of Ru(bpy)₃²⁺ increaced at the detection potential of 1.17 V (vs. Ag/AgCl). Linear relationship was found between the peak area of ECL signal with the mass concentration of dendrobine in the range of 1.0-100 mg·L^-1, with detection limit (3S/N)of 0.045 mg·L^-1. The proposed method was applied to the determination of dendrobine in Dendrobium nobile Lindl, giving recovery rates obtained by standard addition method in the range of 92.0%-105% and RSDs (n=5) were in the range of 2.5%-5.1%.