Betel leaf (Piper betle L.) is a medicinal plant. There betel leaf essential oil content and show a variety of biological activity, including antibacterial. The purpose of this study was to determine the effect of betel leaf essential oil on blood coagulation in patients with factor VIII and IX of blood plasma disorders. Isolation of essential oil made by steam distillation method using two kinds of solvents distilled water and n-hexane. N-hexane extract obtained is separated by liquid-liquid extraction and rotary evaporator. The test results of blood clots increases as the concentration of essential oils, namely essential oils ½ times dilution of 99.67 seconds; dilution ¼ times 127 seconds; dilution 1/8 times 179 seconds; and dilution 1/16 times 242.67 seconds.