The adsorption of Cr6+ on Cr3+was carried out by anion exchangecolumn.The contents of Cr 3+ and total chromium in water-soluble fertilizer were determined by flame atomic absorption spectrometry.The content of Cr 6+ was determined bysubtractionmethod.The effects of the working conditions of the instrument and the flow rate of the test solution through thecolumn on the experimental results were analyzed.The results show that under the optimal experimental conditions，therelative standarddeviation(RSD)of water -soluble total chromium measured value is 1.12%～3.13%，and the RSD of water-soluble Cr3+ measured value is 1.93%～2.93%；the recoveries of Cr 3+are between 98.8% and104.0%，and the adsorption rate of Cr6+is between 97.0% and102.0%.Solid Phase Extraction -Flame Atomic Absorption Spectrometry can be applied to the speciation analysis of chromium in water-soluble fertilizers，and has the advantages of relatively lowcost，easy operation and good reproducibility.