To anastomose tubular biomedical tissues in a reliable and stable joint state with a simple operation.

The member 1 for an anastomosis is formed into a cylindrical shape of an outer shape dimension capable of being inserted into openings at the end parts 2a, 3a of the paired tubular organism tissue 2, 3 with the use of a knitted material obtained by knitting yarn made of bio-compatible polymer. The member 1 has: flexibility for clogging the inner opening so as to be crushed to seal the inner surface by outer force to be added in a radius direction from an external side; heat resistance against temperature higher than the melting point of collagen; and elasticity to open the clogged inner opening by releasing the outer force after heating.