Oenanthe javanica (BI.) DC, 2n = 2x = 22, is an aquatic perennial herb originating from East Asia, and belongs to Oenanthe genus in Apiaceae family. The O. javanica with abundant vitamins and minerals is not only consumed as a vegetable, but has also used as a medicinal agent. Hyperoside, persicarin, and isorhamnetin are the three major substances with pharmacological activities in O. javanica. These substances are shown to possess hepatoprotective, antithrombotic, antiarrhythmic, anti-diabetic, anti- hepatitis B virus, neuroprotective, and anticancer activities.