 This is a prospective, randomized trial comparing different doses of rosuvastatin in patients with acute coronary syndrome post drug-eluting stents implantation. Through the study, the investigators aim to evaluate the effects of high dose rosuvastatin calcium on target vessel endothelialization and non-target vessel plaque stability. Moreover, the investigators may provide mechanically evidence of clinical application of high dose rosuvastatin in patients with acute coronary syndrome. 