Objective:To survey the prevalence and comorbidity of patients with chronic thromboembolic pulmonary hypertension (CTEPH) in Shanxi province from 2018 to 2021.Methods:The data of patients with CTEPH from 2018 to 2021 were extracted from the Health Statistics Direct Reporting System of Shanxi Provincial Health Commission; the population data of Shanxi Province was obtained from the Statistical Yearbook of Shanxi Province. The prevalence rate of CTEPH in Shanxi Province in 2018, 2019, 2020 and 2021 was calculated. The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) was used to identity the specific Charlson comorbidity from other diagnosis on the medical record. The severity of the comorbidity scale was classified as mild (aCCI≤2 points), moderate (aCCI=3-5 points), moderate-severe (aCCI=6-8 points), and severe (aCCI≥9 points).Result:A total of 300 patients with CTEPH were identified in the whole province during the period with the mean age of(65.5±11.5)years, there were 31, 65, 83 and 121 cases in 2018, 2019, 2020 and 2021, and the corresponding prevalence rates were 0.9/10 6, 1.9/10 6, 2.4/10 6 and 3.5/10 6, respectively showing an increasing trend. The patients with CTEPH in this study involved 14 Charlson comorbidities, among which the chronic lung disease was in the highest proportion (198/300, 66.0%), followed by peripheral vascular disease (126/300, 42.0%) and chronic congestive heart failure (121/300, 40.3%). There were 16.3% (49/300) of patients with mild comorbidity, 56.3% (169/300) with moderate comorbidity, 22.3% (67/300) with moderate-severity comorbidity, and 5.0% (15/300) with severity comorbidity. Conclusions:The prevalence of CTEPH in Shanxi province from 2018 to 2021 was 0.9-3.5/10 6 showing an upward trend. The chronic lung disease, peripheral vascular disease and chronic congestive heart failure are the main comorbidities of patients with CTEPH, and mostly with moderate comorbidity.