To provide a medical fixing material excellent in operability; allowing a drug or a medical device to be directly fixed to vital tissue.

The medical fixing material is constituted of a film of a polyion complex formed of a polycationic material and a polyanionic material. The fixing material excellent in biocompatibility is well bonded to the surface of the tissue, a metal, a resin, etc., in the cases of gelation brought about by absorption of water content such as blood in an affected part or an exudate from the vital tissue etc. Consequently, the fixing material permits the drug to be contained for attachment and suture in an organ at an operation in order to provide the affected part with the drug in addition to application of the fixing material to an oral mucous membrane. Furthermore, the operation can be efficiently performed because the fixing material allows the various medical devices such as an indwelling needle, a catheter, a flat clasp, etc., to be securely and simply fixed at the operation.