A high sensitive chemiluminescent magnetic enzyme-linked immunoassay method was established for Escherichia coli O157∶H7 determination.The bacterium antibody was labeled by alkaline phosphatase（ALP） that catalyzed the decomposing of substrate 3-（2-spiroadamantane）-4-methoxy-4（3-phosphoryloxy）phenyl-1,2-dioxetane（AMPPD） to give the light emission.The sensitivity of the method is 8.5×104 Cell/mL with a linear range of 1.0×105—5.0×107 Cell/mL.The intra- and inter-assay CVs are 14.8% and 20.0% in pork samples, respectively.The correlation coefficient of present and the standard plate counting method is 0.981.The experiments with the spiked samples show that this method has great potential to be applied to（detecting） the concentration of Escherichia coli O157∶H7 in a variety of samples.
