Abstract: Object: To prepare monoclonal antibody against Cr³⁺chelate EDTA complex( Cr³⁺- EDTA m Ab) and develop colloidal gold immunochromatographic assay for detecting total chromium content in food( Cr- Strip).Method: The isothiocyanate method was employed to synthesize Cr³⁺- i EDTA- BSA,which was identified by UV and ICP- AES.The hybridoma lines that secrete Cr³⁺- EDTA m Ab were established by cell fusion and Cr³⁺- EDTA m Ab were induced from in vivo method and their immunological properties were analyzed. Based on Cr³⁺- EDTA m Ab,Cr- Strip was developed and its traits were verified.Results: Three hybridoma lines were screened out and the best one was 2A11G5. The Kaof Cr³⁺- EDTA m Ab was 2.69 × 109 L / mol and its IC50 against Cr³⁺- EDTA was9.84 μg / L and it had little or no cross- reactivity with other metal ion. The Cr- Strip could be accomplished qualitative detection of Cr³⁺- EDTA in 10 minutes,and its detection limit was 5 μg / L,its coincidence rate was 100%compared with ICP- AES. Conclusion: The high quality Cr³⁺- EDTA m Ab had been generated and the Cr- Strip which was more sensitive had been developed successfully.