Effects of Ginkgo biloba leaf extract (GBE) and its components kaempferol-coumaroyl glucosyl rhamnoside (Kc), quercetin-coumaroyl glucosyl rhamnoside (Qc), ginkolide (G) and bilobalide (B) on blood pressure and on the levels of neurotransmitters in the spontaneously hypertensive rat brain were examined. Blood pressure decreased about 10 mmHg after administration of GBE but without significance. The concentration of norepinephrine increased (3 times) and that of DOPAC was decreased (38%) after administration of Qc. And 3-MT concentration was increased (36%) by Kc administration in striatum. While Qc administration increased the concentration of Ach (260%) and Ch(29%) significantly, B administration increased Ch concentration in cerebral cortex.