Abstract: In this study, we used targeted modification method to extract lignin and hemicellulose from mature latewood of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) successively. We applied nanoindentation technology to study the effects of hemicellulose and lignin on nanomechanical properties of wood cell wall at nanoscale. Results showed that lignin influenced the modulus of elasticity(MOE) significantly (at 0.05 level). The loss of elastic modulus was 653% after delignifing treatment. Hemicelluloses, which act as an interfacial coupling agent between the highly ordered cellulose of the microfibrils and lignin, affected MOE of cell wall significantly (at 0.01 level). The loss of elastic modulus was about 9.16% after being treated with hemicellulose extraction. Hemicellulose and lignin affected the hardness of cell wall significantly (at 0.05 level), which decreased with the degradation of hemicellulose or lignin. After delignifing treatment, the hardness of cell wall decreased by 16.98%, while it only decreased by 0.87% after hemicelluloseextracting treatment.