In a previous part, it was reported that the peritoneal exudate obtained by intraperitoneal inoculation of R. tsutsugamushi into guine-pigs previously injected with chlorpromazine was excellent antigen for the compliment fixation test. In the present part, the author investigate d the specificity of this compliment-fixing antigen to Tsutsugamushi disease. The results are summarized as follows: 1) In the presence of the sera of fleck fever, typhoid fever, leprosy, tuberculosis patients and pregnant women, the antigen of peritoneal exudate of R. tsutsugamushi did not show any significant suppresion of hemolysis. 2) In the sera of Tsutsugamushi disease patients, the antigen of every strain of R. tsutsugamushi, even highly diluted one, showed the suppresion of hemolysis. In short, the compliment fixation test with the antigens of Karp, Mitani and Tanizawa strains was quite specific to Tsutsugamushi disease and did not show any group reaction; this fact suggests that this compliment fixation test is of great use for the diagnosis of Tsutsugamushi disease.