Intraperitoneal injection of adsorbed diphtheria-purified pertussis-tetanus combined vaccine (DPPT) often causes an ascites-accumulating (A-A) reaction in guinea pigs. Those vaccines which caused A-A reaction increase the vascular permeability (VP) of the skin tissue at the intracutaneous injection sites. A total of 23 lots of DPPT were assayed for A-A and VP-increasing activities. A positive correlation between the volume of ascites accumulated and the intensity of VP was significant. Other kinds of aluminum-adsorbed (Al-Ad) vaccines such as Al-Ad tetanus and Al-Ad diphtheria-tetanus combined and Al-Ad hepatitis B vaccines induced little or no A-A reaction. These results were discussed from the viewpoint of quality control in the process of the production of DPPT.