A rapid and simple method using capillary electrophoresis (CE) with chemiluminescence (CL) detection was developed for the determination of levodopa. This method was based on enhance effect of levodopa on the CL reaction between luminol and potassium hexacyanoferrate(III) (K3[Fe(CN)6]) in alkaline aqueous solution. CL detection employed a lab-built reaction flow cell and a photon counter. The optimized conditions for the CL detection were 1.0×10−5Mluminol added to the CE running buffer and 5.0×10−5MK3[Fe(CN)6] in 0.6MNaOH solution introduced postcolumn. Under the optimal conditions, a linear range from 5.0×10−8 to 2.5×10−6M (r = 9991), and a detection limit of 2.0×10−8M (signal/noise = 3) for levodopa were achieved. The precision (R.S.D.) on peak area (at 5.0×10−7Mof levodopa, n = 11)was 4.1%. The applicability of the method for the analysis of pharmaceutical and human plasma samples was examined. GX毛細管電泳儀(紫外檢測)CL1020