PROBLEM TO BE SOLVED: To provide a bioabsorbable tissue reinforcing material which is excellent in handleability, can sufficiently follow fine irregularity of a biological tissue and can sufficiently prevent leakage of a body fluid and leakage of air even when used in combination with a minimal fibrin paste.SOLUTION: There is provided a bioabsorbable tissue reinforcing material comprising a nonwoven fabric comprising a bioabsorbable material having an average fiber diameter of 0.9 to 7.0 &mum.