Abstract: The differential pulse anodic stripping voltammetric determination of trace Se in water using a flow-through cell with a tubular gold electrode was reported. The tubular electrobe was easy to be constructed and operated, and reguired only small volume of sample. The signal obtained was stable and high reproducible. In a medium of 0.8Msulfuric acid, a sensitive stripping peak of Se at +0.88v(VS S. Ag/AgCl) was observed. The detection limit was showen to be 0.02ppb.Alinear dependence of peak height on concentration of Se over a range of 10^-10 to 10^-8 g/ml was also observed. It was used to determine trace selenium in water with satifactory result.The current-concentration equations for the differential pulse anodic stripping voltammetry on a tubular electrode have been theoretically derived and experimentally verified.