Crataegus tar-llzacetijolia (Lam.) Pers. (Rosaceae) tiiriiniin yaprak ekstresinin kan baslnc~ ve kalp frekans~ iizerine olan etkisi atropin, a-bloker ve P-bloker kullanllarak incelendi. C.tanacetifolia yaprak ekstresinin tansiyon dii~iiriicii etkisi bulundugu tespit edildi.Crataegus tar-llzacetijolia (Lam.) Pers. (Rosaceae) tiiriiniin yaprak ekstresinin kan baslnc~ ve kalp frekans~ iizerine olan etkisi atropin, a-bloker ve P-bloker kullanllarak incelendi. C.tanacetifolia yaprak ekstresinin tansiyon dii~iiriicii etkisi bulundugu tespit edildi.

The effects of the leaf extracts of Crataegw tanacetifolia cam.) Pers. (Rosaceae) on blood pressure and heart rate have been examined by using atropin, aand f&blokers. It have been found that the leaf extracts of C.tanacetifolia have hypotensive effects.Today cardiovascular diseases are one of the most important reason of human death. In U.S.A. more than half of the total death are caused by cardiovascular diseases (1).In the studies made by Craraegw species was shown that these species are effected especially on cardiovascular system (2,3). At this point Crataegus becomes more important. The use of Crataegus species for medicinal treatment have been started in the second half of 19. yy. for treatment of cardiovascular diseases. It is known that Crataegus species were used to treat angina pectoris in U.S.A. (4). The Cratueg~is extracts have anti-arrhythmic effects and have been found effective in the management of tachicardia (5). It is reported that Crataegus have treatment effect on cardiovascular diseases especially on normalizing hypertension (6).