Thermal gravimetric analysis technique was employed to study the basic combustion characteristics of carbonized sewage sludge. This was to use carbonized sewage sludge as alternative fuel. The basic combustion characteristics of excess and digested sewage sludges that were discharged from D city were dried and carbonized. The physical and chemical properties of these samples were analyzed, and non-isothermal analysis was conducted at the heating rates of 5, 10, 15, and 20℃/min using TGA to find the basic combustion characteristics. According to the interpretation of the results of non-isothermal analysis by Friedman method, the activation energy in the section of highest weight loss was 27.07kcal/mol for carbonized excess sewage sludge, 46.61kcal/mol for carbonized digested sewage sludge. The combustion reaction order (n) for carbonized excess sewage sludge, carbonized digested sewage sludge was 7.38 and 9.44 respectively, and the frequency factor was 3.00×107 and 3.45×1015 for each.