Agents targeting at renin-angiotensin system (RAS) blockade are very commonly used by physicians of cardiology and nephrology, owing to the utmost importance of RAS in the pathogenesis of both the cardiovascular and renal diseases.ACEI and ARB are sometimes referred to as "reno-protecting" drugs because of their specific effect to decrease proteinuria, a faithful surrogate marker of kidney disease progression.Many clinical studies have demonstrated that more complete RAS blockade with either ACEI or ARB, or dual agents, decreased proteinuria more effectively.