By using an LKB-2277 Bioactivity Monitor, complete thermograms of aerobic growth at 37 degrees C have been obtained for Escherichia coli. The amount of glucose consumed S-c has been measured by the glucose oxidase method, and its relationship with the quantities of heat evolved Q(t) has been studied. Different linear relationships exist at different phases of Q(t) and S-c, indicating that there are different metabolic controlling processes in the growth of E, coli. The turning point of the different metabolic controlling processes can be determined from the thermograms. Furthermore, through studies on the relationship between the dry weight of cells produced ($) over bar W and S-c together with the relationship between ($) over bar W and time t, the conclusion can be drawn that the different metabolic controlling processes reflected in the relationship between Q(t) and S-c are just the change of the synthesising power of the cells.