Abstract: To investigate the variation of pore structure characteristic during calcium-enriched bio-oil calcination process, the thermal decomposition of calcium-enriched bio-oil (CEB) was tested in a thermogravimetric balance. The results show that there are three reaction stages: the formation of CO₂ and H₂O, the decomposition of organic carboxylic acid calcium salt, and the decomposition of calcium carbonate. The calcium oxide particles obtained from decomposition and calcination of CEB were analyzed to determine the physicochemical characteristics. It can be noted from the pore structure parameters that the decomposition of organic carboxylic acid calcium salt has important influences on the pore structure of product. The cavitation by gas release and the carbonization deposition of macromolecular compound coexist in the temperature range of 450℃~600℃, but the latter is dominated. The carbonization deposition of macromolecular compound mainly occurs in the range of 500℃~600℃. After 600℃, with the decomposition of calcium carbonate and the release of carbon dioxide, new micropores are formed in calcined product. Under the same calcination temperature, the pore characteristic of CEB calcined product is obviously superior to that of calcium carbonate.