AbstractChinese Fir wood (Cunninghamia lanceolata (Lamb.) Hook) was subjected to extraction treatments with sodium chlorite (NaClO2) for delignification, as well as with sodium hydroxide (NaOH) at different concentrations for extraction of hemicelluloses. The wood was examined using a Fourier Transform Infrared (FT-IR) spectrometer and microtension technique to track changes in the chemical and the micromechanical properties of the cell wall. The results of the microtensile tests indicated that the hemicelluloses caused more damage to the mechanical properties of the cell wall than lignin. The micromechanical properties that occurred with degradation of chemical components underlined the key role of hemicelluloses in maintaining the integrity of the cell wall.