This is a 12-week, randomized, open-label,,multicenter, Phase IV study exploring LDL-C lowering efficacy of Rosuvastatin 20 mg/d compared to 10 mg/day Chinese ACS patients.The Randomized Treatment Period is preceded by a 24hours Screening Period. The study flow chart (Figure 1) depicts the 2 periods which comprise the study. These periods are described as follows:

1. Screening Period (Day -1 through Day 1) This period consists of Visits 1 and 2. Subjects entering the Screening Period are required to meet the inclusion criteria. All subjects will be instructed to follow the current TLC(therapeutic lifestyle change)dietary guidelines for the duration of the trial.
2. 12-week Randomized Treatment Period (Day 1 through Week 12) This period consists of Visits 2, 3, 4, and 5. Eligible subjects will be randomized at Visit 2 to each treatment group: Rosuvastatin 20 mg orRosuvastatin10 mg. Treatment will be administered once daily for 12 weeks.

A total of 450valid subjects in each of the Rosuvastatin arms are required, in order to test the hypothesis of superiority for comparison of LDL-C levels between Rosuvastatin20 mg and Rosuvastatin10 mg(see Section 6.1 for more details).

The Study visit schedule(Table 2) indicates the number and timing of the planned visits. The visit schedule must be within time window. At the final visit, it is the responsibility of the investigator to ensure the subject is offered an selected appropriate type of lipid-lowering therapy.

Scheduled Visit3,4,5 will have a visit window of ±2 days. Subjects who attend a clinic visit without fasting (at least 12 hours) should be asked to return within 2 days for another clinic visit after fasting for at least 12 hours.

Inclusion Criteria:

• 18-80 year old males and non-child-bearing period females.
• Clinical diagnosed with acute coronary syndrome including NSTE-ACS ,MI and STEMI.
• Patients with STEMI((ST segment elevation myocardial infarction) and NSTEMI(non-ST segment elevation myocardial infarction) will be recruited within 48 hours of symptom onset.
• The LDL-C≥70mg/dL one week before randomization.
• The TG<500mg/dL one week before randomization.
• No cholesterol-lowering drugs (including lipid lowering dietary supplements, antioxidants, or food additives) during 4 weeks before randomization.
• Sign the ICF(inform consent form)

Exclusion Criteria:

• Acute pulmonary edema, severe congestive heart failure,
• acute moderate mitral regurgitation, acute ventricular septal perforation,
• severe arrhythmia (ventricular fibrillation, sustained ventricular tachycardia, complete heart block), sepsis, acute pericarditis,
• any evidence of systemic or pulmonary embolus within the preceding 4 weeks.
• Coronary artery bypass graft within the preceding 3 months; percutaneous coronary intervention within the preceding 6 months.
• A history of hypersensitivity of statins and other severe complication.
• child-bearing women
• hypothyroidism,
• active liver disease or dysfunction including agnogenic serum transaminase sustained elevation or higher than 3 times ULN(upper limit of normal)
• severe anemia (hemoglobin,hematocrit < 28%),
• Patients with myopathy or serum creatine kinase > 3 times the upper limit of normal not caused by myocardial injury.
• A history of psychiatric disorders
• A history of jejunoileal bypass or gastric bypass surgery
• Currently take steroids therapy
• Currently take phenytoin sodium,phenobarbital,carbamazepine (which may primary efficacy endpoint)
• Diagnosed with malignant within 5 years
• Severe renal function damage (creatinine clearance rate<30 ml/min)
• Concurrent use ciclosporin