PURPOSE: To obtain a large-core diameter porous cellulose in which pores larger than about 2μ are relatively homogeneously distributed, by freezing liquid drops of a cellulose solution and regenerating the cellulose after the solvent is removed by extraction or deprived of its solvency.

CONSTITUTION: A cellulose solution is divided into liquid drops, and these drops are frozen by cooling to a temperature lower than the solidifying temperature. The solvent in the frozen drops is removed by extraction or deprived of its solvency to obtain the purpose porous particles. The pores of the porous cellulose particles should have a diameter above about 2μ, preferably, most of them should be larger than 5μ. When it is smaller than this value, the free movement of a fluid or a substance in the pores of the cellulose particles cannot be realized, and their use is limited. The upper limit of the size of the pore is usually several hundred μ, preferably, below 200μ. The porous particles are suitable as, e.g., a carrier for catalysts, enzymes or drugs, a material for ion exchangers, or adsorbents or a microcarrier for cell culture.