An immunochromatographic assay（ICA） method for the detection of chromium ions（Cr3+） was developed.Colloidal gold particles coated with affinity purified monoclonal anti isothiocyanobenzyl-EDTA（iEDAT）-chelated Cr3+ antibodies were used as detection reagent，and the strip was prepared by arraying the synthetic Cr3+-EDTA-BSA and goat anti-mouse immunoglobulins on cellulose nitrate film to form the test（T） band and control（C） band.The prepared strip was used to detect Cr6+ when it was reduced to Cr3+ by NaHSO3.The visual lowest detection limities（LDL） of the test strip was as low as 50 μg/L.The test trips showed negligible cross-reactivities with 10 heavy metals except for 1 000 μg/L Fe3+-EDTA.The determination result of water samples containing chromium standard by the prepared strip was consistent with that by ICP.Because of its sensitivity，specifity，low cost and fast result（within 5 min），the test strip is especially suitable for the on-site large scale screening on Cr-contained water samples and many other applications.