Objective To explore the relationship between serum low-density lipoprotein cholesterol (LDL-C) and prognosis of patients with coronary atherosclerotic heart disease (CHD) who undergo the percutaneous coronary intervention (PCI). Methods Clinical data and LDL-C levels of 492 patients with CHD 1 d and 1, 6, 12, and 24 months after PCI were collected. Patients were divided into groups according to LDL-C levels (＜1.81, 1.81-2.58, 2.59-3.36, and ≥3.37mmol/L or ＜70, 70~99, 100~129, and ≥130 mg/dL) at each time point. The relationship between end-point events (include cardiac death, recurrence of myocardial infarction, revascularization of target blood vessel, recurrence of angina, recently developed heart failure or existing heart failure becoming severe, and stroke, etc) during follow-up period and LDL-C levels were analyzed. Results The mean levels of LDL-C of patients 1 d and 1, 6, 12, and 24 months after PCI were (3.07±1.05), (2.03±0.75), (2.06±0.71), (2.13±0.82), and (2.17±0.89)mmol/L, respectively. The differences of incidence of end-point events of patients with different LDL-C levels 12 and 24 months after PCI were statistically significant (P<0.01). Results of logistic regression analysis showed that age, diabetes, stroke, LDL-C levels 12 and 24 months after PCI were independent predicting factors of the incidence of end-point events. Compared with patients whose LDL-C levels were below 1.81 mmol/L, the risk of developing end-point events of patients whose LDL-C levels were between 2.59-3.36 and above 3.37 mmol/L 12 and 24 months after PCI was higher. Conclusion The risk of developing cardio-cerebrovascular events of old patients or patients with diabetes or stroke after PCI is high. Compared with patients whose LDL-C levels are below 1.81 mmol/L, the risk of developing cardio-cerebrovascular events of patients whose LDL-C levels are above 2.59 mmol/L 12 and 24 months after PCI is higher.