The peritoneal absorptive function test by the use of BSP, the Matsunaga's and Matsuda's methods by the use of PSP were observed on the rabbits under the same condition. And the results were as follows. 1. In the rabbits with kidney damage by corrosisve sublimate, the BSP method showed the same value with healthy cases, but the decline of excretion, the delay of arrival time to the maximum value and the transformation of excretion curve were observed on the PSP method. In other words, the factor of kidney damage could be removed in the BSP method. 2. Making the BSP and PSP methods on the rabbits with tuberculous peritonitis by the intraperitoneal administration of tuberculous bacillus, abnormal findings were not observed, at 8-10 th day after the injection of tuberculous bacillus, on both of method, and the decline of maximum value, the delay of arrival time to the maximum value and the decline of absorptive function were observed, after 20-22 days, on both of method, but the reversion to normal value was observed, after 40-42 days, on both of method. In other words, the same tendency could be observed on both of BSP and PSP methods.