Provided is a production method of a tissue regeneration material whereby a cell suspension can be seeded, stably without being wasted, and cultured on a porous support (porous body) having relatively large pores, i.e. pores that make it difficult to keep the cell suspension inside the support. The method comprises: contacting a bottom surface of a porous body (11) to a surface of a holding plate (1) being a resin plate or glass plate having a contact angle to water of 15 to 90°, the porous body being formed of a bioabsorbable polymer material, having a thickness of 2 to 100 mm, an interconnected porous structure with a pore diameter of 180 to 3500 µm and an average pore diameter of 350 to 2000 µm, a porosity of 60 to 95%, and a compressive strength of 0.05 to 1 MPa, and being filled with a cell suspension (12) having a cell density of 5 × 10 6 to 1 × 10 8 cell/ml； and thereafter arranging the holding plate to be on the porous body when seen in the gravity direction, and keeping the porous body still in the air in a state that the weight of the holding plate is not applied to the porous body, to thereby seed cells on the porous body.
