The commercially available montmorillonite KSF is utilized as efficient acidic catalyst in organic synthesis chemistry. In this study it is used as a photoactive reagent in a heterogeneous system. A series of experiments of the degradation of bisphenol A (BPA) as a model organic pollutant in montmorillonite KSF suspended solutions under UV-vis irradiation (metal halide lamp, lambda >= 365 nm) were investigated. It is found that BPA could be effectively photodegraded in suspension. The BPA photodegradation is dependent on the pH of the solution and dosage of clay minerals, and it is more effective for BPA to be degraded at pH 4; the degradation rate of BPA increased with the concentration of clays in the range of 0.5 g/L to 5 g/L. The photodegradation rate of BPA is fitted well into the Langmuir-Hinshelwood equation. Results also indicate that the carboxylate and dissolved oxygen could efficiently enhance the degradation rate, and the role of carboxylate in accelerating the photodearadation of BPA follows the order: pyruvate > oxalate > citrate.