The present invention aims to provide a method for producing a porous tissue regeneration substrate that allows a wide choice of solvents and easy adjustment of the bulk density and pore size of the porous substrate. The present invention also aims to provide a method for producing an artificial blood vessel and an artificial blood vessel. The present invention relates a porous, tubular artificial blood vessel containing a bioabsorbable material, the artificial blood vessel including: a skin layer having a relatively small pore size as an innermost layer; and a porous layer positioned around the skin layer and having a relatively large pore size.