Objective To analyze the clinical risk factors of pulmonary hypertension (PH) associated with chronic obstructive pulmonary disease(COPD). Methods A total of 55 hospitalized patients from 2014 to 2015 were enrolled in the study and were classified into three groups according to pulmonary artery systolic pressure (PASP) with echocardiography as follows: the mild group (36≤PASP＜50 mmHg), the moderate group (51≤PASP＜70 mmHg) and the severe group (PASP≥70 mmHg). Clinical data were recorded and retrospectively analyzed. Results The average age of all patients was (75.3±11.6)years. Echocardiography showed a mean PASP was 52.6±15.1 mmHg. Age, hematocrit (HCT), partial pressure of carbon dioxide (PaCO₂), the oxygen partial pressure (PaO₂), D-dimer and right ventricular (RV) diameter (>20 mm) were associated with moderate-to-severe PH on an univariate regression analysis, while RV (diameter >20 mm)[odds ratio (OR)=4.53, 95% CI: 2.83～7.27], HCT(OR=51.82, 95% CI: 2.34~1149.02) and PaCO₂ (OR=1.02, 95% CI: 1.00-1.03), to these patients, were independent risk factors using the multiple logistic regression analysis. Conclusion PH related to respiratory diseases is mostly mild-to-moderate. Haemoptysis,high levels of RV diameter, HCT and PaCO₂ suggest a serious condition of patients with PH related to chronic respiratory disease.