In the present paper,a quantitative linear model between a series of concentrations of E.coliO157:H7 and counts by BPCL ultra weak luminescence analyzer was built up.And the influences of four different buffers with the same pH (pH=7.4),Tris-HCl,PBS,KH₂PO₄-NaOH and Na₂HPO₄-C₆H₈O₇,and five different chemical substances with the same mass concentration (10 g·L),NaCl,KCl,NaOH,MgCl₂ and NaH₂PO₄ on ATP bioluminescence were compared.The results showed that Tris-HCl was a suitable buffer for dilution,since it could distinguish well between different concentrations and had the lowest background signals.And MgCl₂ could intensify luminescence distinctly,while the other four chemical substances decreased luminescence,of which NaOH decreased luminescence most obviously.Moreover,ATP bioluminescence was correlated well with conventional culture methods (r=0.96),and the detection limit was 103 cells·mL^-1.