The colour reaction between o-hydroxyhydroquinonephthalein and vanadate ion in the presence of hexadecyltri-methylammonium chloride and L-ascorbic acid as a reductant was discussed. And the spectrophotometric determination of vanadium utilizing the colour reaction system in micellar media was proposed at about pH 5.4. Beer's law was obeyed in the concentration range 0-8 μg of vanadium at 540 nm. The apparent molar extinction was 8.7 × 1041 mol−1cm−1with Sandell sensitivity of 0.0006 μg/cm2. This proposed method was relatively simple and sensitive, and then its applications for the waste water, river water, rain water, etc. were discussed.