Aim:To study the effect of genistein(GST)on carotid baroreceptor activity(CBA).Methods:The functional curve of carotid baroreceptor(FCCB)was con-structed and the functional parameters of carotid baroreceptor were measured byrecording sinus nerve afferent discharge in anesthetized male rats with perfusedisolated carotid sinus.Results:GST at 50,100,and 200 μmol/L inhibited theCBA,which shifted FCCB to the fight and downward,with a marked decrease inpeak slope and peak integral value of carotid sinus nerve discharge in a concen-tration-dependent manner.Pretreatment with 100 μmol/L N~G-nitro-L-arginine me-thyl ester,an inhibitor of nitric oxide synthase,did not affect the effect of GST onCBA.Pretreatment with 500 nmol/L Bay K8644,an agonist of calcium channels,could completely abolish the effect of GST on CBA.A potent inhibitor of tyrosinephosphatase,sodium orthovanadate(1 mmol/L),could attenuate the inhibitoryeffect of GST.Conclusion:GST inhibits CBA,and the effect may be mediated byprotein tyrosine kinase inhibition and a decrease in Ca~(2+)influx through the stretch-activated channels. Aim: To study the effect of genistein (GST) on carotid baroreceptor activity (CBA). Methods: The functional curve of carotid baroreceptor (FCCB) was con-structed and the functional parameters of carotid baroreceptor were measured by sinusoids afferent discharge in anesthetized male rats with perfusedisolated carotid sinus. Results: GST at 50, 100, and 200 μmol / L inhibited the CBA, which shifted FCCB to the fight and downward, with a marked decrease in peak slope and peak integral value of carotid sinus nerve discharge in a concen- tration -dependent manner. Treatment with 100 μmol / LN ~ G-nitro-L-arginine me-thyl ester, an inhibitor of nitric oxide synthase, did not affect the effect of GST onCBA.Pretreatment with 500 nmol / L Bay K8644, an agonist of calcium channels, could completely abolish the effect of GST on CBA. A potent inhibitor of tyrosine phosphatase, sodium orthovanadate (1 mmol / L), could attenuate the inhibitory effect of GST. Conflusion: GST inhibits CBA, and the effect may be mediated bypro tein tyrosine kinase inhibition and a decrease in Ca ~ (2+) influx through the stretch-activated channels.