Process and kinetics of thermal decomposition of humic acid were studied with TG-DTG techniques. Thermal decomposition temperature of humic acid was in the range of 284.65-417.16℃. The structure of humic acid was characterized with FT-IR

1H NMR and 13C NMR. The kinetic parameters

including activation energy and pre-exponential factor of the thermal decomposition process of humic acid were calculated with the Flynn-Wall-Ozawa (FWO)

Kissinger and Šatava-Šesták method respectively. Activation energy and logarithmic value of pre-exponential factor were found to be 210.83 kJ·mol-1 and 17.55

respectively. Moreover

reaction order and mechanism of thermal decomposition and thermodynamic parameters were also studied. Thermal decomposition of humic acid was a second-order reaction

and the mechanism of the decomposition process was obtained. The maximal used temperature of humic acid maintaining one-minute lifetime in N2 atmosphere was 278℃. Meanwhile

the thermodynamic paramaters of ΔH≠

ΔS≠ and ΔG≠ were calculated as 67.99 kJ·mol-1

-164.83 J·(mol·K)-1 and 176.36 kJ·mol-1

respectively.