Hypertension is still one of the major preventable risk factor for cardiovascular as well as cerebrovascular diseases globally, including ischaemic heart disease, heart failure, and renal impairment. Despite knowledge on hypertension and the availability of effective antihypertensive medications have progressed dramatically in recent years, the rate of uncontrolled hypertension ( reached 90%) remains high in China[1]. Among those with uncontrolled hypertension，it has been reported that 8.9% in all individuals with hypertension, and 12.8% in the hypertensive drug-treated population[2] are attributed to resistant hypertension. Resistant hypertension has been defined by AHA as high blood pressure (BP) in spite of appropriate lifestyle interventions and treatment of three or more different types of antihypertensive drugs at optimal dose, including at least one diuretics[3,4] or achieving adequate BP control with optimal doses of 4 or more antihypertensive drugs. At present, not many specifically designed prospective researches concerning resistant hypertension are available. The prevalence of resistant hypertension is not well established and most knowledge about resistant hypertension derives from cross-sectional analyses and clinical trials. The patients with resistant hypertension have been expected to have server target damage, and worse prognosis than those who are non-resistant, but not well established either in the literature[2]. The purpose of this study is to determine the prevalence of resistant hypertension ascertained with systemic investigation and optimal treatment with antihypertensive drugs in community populations and clinic as well as the prognosis among patients with resistant hypertension compared with those who are non-resistant.