Non-isothermal thermogravimetric analysis experiments were carried out to investigate combustion characteristics of neutral sulfite semi-chemical pulp black liquor solids at a temperature range of room temperature to 800 degrees C with the heating rates of 10, 20, 30, and 50 degrees C center dot min-1. The results show that there are three temperature ranges, namely volatile matter separating process (170-370 degrees C), volatile matter burning process (370-550 degrees C), and fixed carbon burning and alkali metal salts reacting process (550-800 degrees C), in which the black liquor quickly loses weight. The kinetic parameters were determined for the three reaction regions by using the Kissinger method and the Ozawa method. The activation energies were higher by choosing the Kissinger method over the Ozawa method. Kinetic parameters of neutral sulfite semi-chemical pulp black liquor can supply the theory bases for establishing thermal combustion model.