Objective: To investigate the abnormality and distribution of plasma cholesterol levels in single-center hospitalized children. Methods: The blood lipid levels of children aged 2-18 years who had blood lipid test results in Peking University First Hospital from June 2016 to June 2019 were etrospectively analyzed. Cholesterol oxidase method was used for total cholesterol, and high-density lipoprotein cholesterol and low-density lipoprotein cholesterol were detected by clearance method. The counting data were compared with chi-square test. Results: The survey had involved 11 829 children (7 087 were boys and 4 742 were girls). 1 822 (15.4%) children were with elevated total cholesterol, 1 371 (11.6%) children with elevated low-density lipoprotein cholesterol, and 2 798 (23.7%) children with high-density lipoprotein cholesterol reduction. The total number of the children with abnormal cholesterol levels was 4 427 (37.4%). Among the 7 835 children who visited hospital due to the disease not commonly inducing dyslipidemia, 731 (9.3%) had elevated TC, 561 (7.2%) had elevated LDL-C, 1 886 (24.1%) had decreased HDL-C, and 2 576 (32.9%) had abnormal cholesterol levels. Among the children with different diseases, the difference in the incidence of abnormal cholesterol was statistically significant. The top three main groups of the children with increased total cholesterol and low-density lipoprotein cholesterol were “dyslipidemia”, “urinary tract disease”, and “nutritional disease”; The top three main groups of the children with reduced high-density lipoprotein cholesterol were “respiratory diseases”, “dyslipidemia”, “hematological diseases and malignant tumors”. Among the 1 257 blood li-pid test results sent by other departments, 300 cases had abnormal cholesterol levels (23.8%). Among them, there were 70 children with hypercholesterolemia (5.6%), 44 children with increased low-density lipoprotein cholesterol (3.5%), and 224 children with reduced high-density lipoprotein cholesterol (17.8%). There were 365 (4.6%) children with low-density lipoprotein cholesterol ≥140 mg/dL (3.6 mmol/L) who needed to further exclude familiar hypercholesterolemia among the children who visited hospitals due to the disease not commonly inducing dyslipidemia. Conclusion: Children in hospitals have a high incidence of cholesterol abnormalities. Doctors need to pay more attention to the cholesterol diagnosis and management regardless of the discipline, which not only helps to control secondary hypercholesterolemia, but also provides the possibility of detecting familial hypercholesterolemia in time.