Hypertension and related cardiovascular diseases are the leading causes of death in many countries. The etiology of human essential hypertension is largely unknown. It is highly likely that hypertension is a complex and multifactorial disease resulting from the interaction of multiple genetic and environmental factors. Persistent hypertension is one of the risk factors for strokes, heart attacks, heart failure and arterial aneurysm, and is a leading cause of chronic renal failure. Animal models of hypertension have been proved to be useful to study the pathogenesis of, and to find a new therapy for, hypertension. New animal models of hypertension are being developed as new insights in to the pathogenesis of hypertension are revealed. The animal models of hypertension share many features which are common to human hypertension. Many of these models have been developed by utilizing the etiological factors that are presumed to be responsible for human hypertension such as excessive salt intake, hyperactivity of rennin angiotensin-aldosterone system (RAAS) and genetic factors. A number of animal models of hypertension each having unique advantages as well as disadvantages has been discussed in this chapter.