Abstract: According to JJF 1059.1-2012 and JJG 1135-2017, the measurement uncertainty in the verification/calibration process of thermogravimetric analyzer (TGA) were evaluated. The results show that the expanded uncertainty of temperature indication error of TGA with differential scanning calorimeter during TGA verification/calibration process was 0.70℃ (k=2). The expanded uncertainty of temperature indication error of TGA was 1.80℃ (k=2). The expanded uncertainty of mass indication error was 12 μg (k=2).