By using an LKB2277 BioActivity Monitor (heat conduction microcalorimeter),stopped flow method,the thermogenetic curves of Escherichia coli growth at 37℃ inhibited by four kinds of heavy metal ions are determined,and parameters such as growth rate constants,inhibitory ratio,half inhibitory concentration etc.were obtained.The experimental results show that heavy metal ions can inhibit Escherichia coli growth obviously,but low concentration of Cu 2+ has a promoting action.The half inhibitory concentrations of Zn 2+ ,Cd 2+ ,Hg 2+ and Cu 2+ are 28.3,10.9,3.19 and 69.6μg.mL -1 ,respectively.Judged from the rate constant,the half inhibitory concentration and the molecular mass,the inhibitory sequence is Hg 2+ >Cd 2+ >Zn 2+ >Cu 2+ .This microclorimetric bioassay for acute cellular toxicity is based on metabolic heat evolution from cultured cells.The assay is quantitative,inexpensive,and versatile;moreover,toxicological information can be obtained with cell from other species of interest. By using an LKB2277 BioActivity Monitor (heat conduction microcalorimeter), stopped flow method, the thermogenetic curves of Escherichia coli growth at 37 ° C inhibited by four kinds of heavy metal ions are found, and parameters such as growth rate constants, inhibitory ratio, half inhibitory concentration etc.were obtained. The experimental results show that heavy metal ions can inhibit Escherichia coli growth obviously, but low concentration of Cu 2+ has a promoting action. The half inhibitory concentrations of Zn 2+, Cd 2+, Hg 2+ and Cu 2+ are 28.3, 10.9, 3.19 and 69.6 μg.mL -1, respectively. Judged from the rate constant, the half inhibitory concentration and the molecular mass, the inhibitory sequence is Hg 2+> Cd 2+> Zn 2+> Cu 2+ .This microclorimetric bioassay for acute cellular toxicity is based on metabolic heat evolution from cultured cells. Assay for quantitative, inexpensive, and versatile; moreover, toxicological information can be obtaine d with cell from other species of interest.