Biomass pyrolysis is one of the most important means to realize effective treatment and efficient utilization of biomass wastes and materials. Therefore, it has great practical significance to research the process and mechanism of biomass pyrolysis. Wood, as a renewable material with a rich source , is a kind of pyrolysis raw material among lots of biomass. As we all know, because of the difference of composition and other aspects, pyrolysis characteristics of different tree species have obvious differences. However, even the same kind of wood such as the heartwood and sapwood of lumber show different pyrolysis characteristics and products in the process of pyrolysis, due to the significant differences in such aspects as microstructure, chemical composition and the amount of each component, which is studied feild in this paper. In the experiment, sabina chinensis, a kind of common landscaping, are taken as test material, whose heartwood and sapwood are clearly distinct. In order to research the pyrolysis differences between heartwood and sapwood, TG-FTIR method is used to obtain the thermogravimetric curves and volatile spectrograms during the process. Results elucidated that the content of cellulose, hemicellulose, lignin and extracts have a remarkably effect on both heartwood and sapwood. On account of higher content of hemicellulose and lignin, the heartwood of sabina chinensis showed higher weight loss ratio than sapwood during the early and late stages. Whats more, higher content of extracts increased the weight loss ratio of heartwood in the medium stage, which reduced the differences between heartwood and sapwood. On contrary, sapwood with more cellulose had more obvious weight loss during 300~380 ℃ and higher weight loss ratio in the DTG curve. In addition, the infrared spectrum indicated that both heartwood and sapwood produced almost same volatiles, but there were differences in amount. And when the pyrolysis came to the maximum weight loss velocity, volatiles produced increased significantly. Moreover, sapwood produced more organic compounds, while heartwood produced more water and CO2.