The pharmacological action of 6 main Kampo formulations (1.Mao -to: [Japanese pictograph see text] MA HUANG TANG; 2. Shimbu -to: [Japanese pictograph see text]: ZHEN WU TANG; 3. Ninjin -to: [Japanese pictograph see text] : REN SHEN TANG; 4.Shigyaku-san: [Japanese pictograph see text] : SI NI SAN; 5.Keishi-to: Japanese pictograph see text] : GUI ZHI TANG; 6. Shimotsu - to: [Japanese pictograph see text] : SI WU TANG) on circulatory and autonomic nervous system were studied. 7 healthy adult males( age, 22.3 +/- 1.8 years old ) had 6 basic Kampo formulations, followed by noninvasive measurement of systolic blood pressure (SBP), mean blood pressure (MBP), diastolic blood pressure (DBP), heart rate (HR), stroke volume (SV), cardiac output (CO ), cardiacindex (CI), total peripheral resistance (TPR) by means of systolic area method of brachialsphygmography, every 30 minutes for 2 hours. As results, Mao - to induced an increase of BP,HR,SV,CO and CI, but a decrease of TPR. Keishi - to induced an increase of SBP and SV, and Shimotsu-to induced an increase of DBP and MBP, HR was slowed during former period after oral administration of Shigyaku - san, and later period after oral administration of Shimbu-to and Shimotsu-to. Regarding autonomic activity, Mao-to(former period of experiment ), Shimbu - to and Shimotsu-to induced supression of sympathetic activity, on the other hand, Mao-to (later period of experiment ) and Shiyaku - san showed a tendency of parasympathomimetic action. Mao -to induced the strongest activation of circulatory system of 6 main farmulations, and showed change of autonomic nervous activity, however, the change of circulatory and automonic nervous activity were not coincident each other. It was speculated that comprehensive mechanism of Mao-to were not only dependent of ephedrin, main active constituent of Mao, but also dependent on Keishi's vasodilatory action in it. Ninjin -to showed no actions on circulatory or autonomic system. This is indicated that there are difference of actions on circulatory and autonomic nervous system among 6 main Kampo fromulations.