Aim To observe the effect of different atorvastatin calcium loading doses on prognosis of unstable angina pectoris （UAP） patients before percutaneous coronary intervention （PCI）. Methods 90 UAP patients were randomly divided into 3 groups （30 patients per group）,after admission,the low-dose group was given 20 mg of atorvastatin calcium everyday in combination with 20 mg of atorvastatin calcium 2 h to 4 h before PCI.The medium-dose group was given 40 mg of atorvastatin calcium everyday in combination with 40 mg of atorvastatin calcium 2 h to 4 h before PCI.The high-dose group was given 60 mg of atorvastatin calcium everyday in combination with 60 mg of atorvastatin calcium 2 h to 4 h before PCI.All patients underwent PCI within 48 h to 72 h after admission.Observe the changes of creatine kinase isoenzyme （CKMB）,cardiac troponin I （cTnI）,high-sensitivity C-reactive protein （hs-CRP） of each group before and after PCI and the major adverse cardiac events （MACE） within 30 days after PCI. Results cTnI and hs-CRP of high-dose group after 24 hours of operation were significantly lower than the low-dose group （P<0.05）.The incidence of myocardial infarction related to PCI of low-dose group,medium-dose group and high-dose group of patients was 23%,13% and 0% （P<0.01） respectively.The incidence of MACE of high-dose group was significantly lower than low dose-group （23% versus 0%,P＝0.005）.The follow-up for 30 days after PCI,three groups had no death and target vessels reascularization event occur. Conclusion Short-term pretreatment with 60 mg atorvastatin calcium each day can reduce significantly procedural myocardial infarction in UAP patients undergoing elective PCI.