Abstract: 【Objective】 In naturally porous materials such as bamboo and wood, pore structure is an important factor that affects the properties. The present study utilized mercury intrusion porosimetry(MIP)and scanning electron microscopy(SEM)to quantitatively characterize and visually inspect the pore structure of bamboo and wood materials. The porous structures of bamboo and wood materials were compared and analyzed, and the pore structure was correlated with the bamboo/wood microstructure. 【Method】Moso bamboo(Phyllostachys heteyocycla cv. Pubescens)and Pinus sylvestris L. lumber were used as the experimental materials. The MIP method involved the quantitative testing of parameters, including porosity, cumulative pore volume, pore diameter distribution and specific pore areas, to identify the characteristics of the pore structure. The SEM method was a direct visual inspection of the microstructures(moso bamboo: vessels, parenchyma cells, fiber cells, pits, et al.; P. sylvestris L.: tracheids, ray parenchyma cells, pits, et al.). The pore diameter ranges found in the microstructure of both materials can also be obtained from SEM. 【Results】 Porosity(moso bamboo: 47.58%, P. sylvestris L.: 67.16%)and cumulative intrusion(moso bamboo: 0.633 mL/g, P. sylvestris L.:1.596 mL/g)indicated that the pore volume in moso bamboo was much lower than P. sylvestris L. lumber, and the comparison of pore area(moso bamboo: 82.04 m²/g, P. sylvestris L.: 18.16 m²/g)and median pore diameter(moso bamboo: 33.8 nm, P. sylvestris L.: 445.0 nm)indicated that the pore diameter in moso bamboo was relatively small(approximately 32.4 nm)while pore diameter in P. sylvestris L. lumber was larger(mainly 226.7 nm or 7 082.3 nm). The correlation of the MIP and SEM results revealed that the pores with diameter of 11.3-100 μm in moso bamboo corresponded to vessels, parenchyma cells and fiber cells in ground tissue, and the pores with diameter of approximately 835.0 nm mainly corresponded to the pits in fiber cells in ground tissue. The pores with diameter of approximately 20 μm corresponded to the tracheids of P. sylvestris L. lumber, while the pores with diameter of approximately 7 082.3 nm corresponded to the aperture of boarded pits and ray parenchyma cells. Additionally, pores with diameters below 1 μm were mainly located in the margo of boarded pits and cell walls. 【Conclusion】 MIP and SEM were effective for the characterization of pore structure in both moso bamboo and P. sylvestris L. lumber. The test methods permitted the analysis of the causes of different properties of bamboo and wood materials. However, when the MIP method was used to test the pore diameter distribution, some large pores were regarded as small pores because of the bottle neck effect; therefore, the accuracy of the test result was affected. Thus, pore morphology must be considered to produce a comprehensive and accurate characterization of the pore structure in bamboo and wood materials.