Specific antiserum against T-kininogen was prepared in rabbits, using T-kininogen purified from rat plasma. The antigenic activity of T-kininogen was completely lost with the release of kinin from native kininogen by cathepsin D treatment. In the determination for T-kininogen in rat plasma and pouch fluid, there was a close relationship between the single radial immunodiffusion method and the amount of total kinin released by trypsin treatment using biological assay. The kininogen levels in plasma and pouch fluid were determined and found to be related to the inflammatory responses, using a single radial immunodiffusion method. Subsequently, the increase in T-kininogen levels in plasma and pouch fluid were not in parallel with the granuloma tissue formation and exudation. However, a significant positive correlation was observed between the total T-kininogen in pouch fluid and the volume of pouch fluid.