Abstract: A novel hierarchical porous carbon aerogel (HPCA) was fabricated and its nanostructure was investigated by SEM and N₂ adsorption. The methylene blue (MB) adsorption properties of the HPCA in water were studied. It is found that the HPCA has a hierarchical micro-, meso- and macropore structure. Its BET and micropore surface areas are 512 and 359 m²·g^-1, respectively. The MB adsorption capacity increases with adsorption time, speed of stirring, temperature and pH value, and the MB removal efficiency can reach 99.8% under optimized conditions. The adsorption kinetics can be well described by a pseudo-second-order equation and the adsorption is controlled by liquid film diffusion in the initial stages and intraparticle diffusion later.