A surgical sealant comprising a first agent containing a hydrophobically-modified gelatin derived from a cold-water fish, and a second agent containing a water-soluble molecule for crosslinking, wherein the water-soluble molecule for crosslinking is at least one kind selected from the group consisting of poly acids and acid anhydrides having two or more active ester groups, and aldehyde compounds having two or more aldehyde groups, the hydrophobically-modified gelatin derived from a cold-water fish is a gelatin in which at least a part of amino groups of side chains of a gelatin derived from a cold-water fish has been substituted by hydrophobic groups, and the hydrophobic groups are linear chain aliphatic groups each having 8 to 18 carbon atoms, with a substitution rate (number of moles of hydrophobic groups / (total number of moles of hydrophobic groups and reactive amino groups in gelatin) ×100) of 3 to 20 mol%.
