Objective To investigate the clinical features and related risk factors of chronic obstructive pulmonary disease (COPD) complicated with pulmonary hypertension (PH). Methods A retrospective analysis was carried out on 702 COPD patients admitted to our department of respiratory diseases from January 2015 to January 2016. According to complicated with PH or not, they were assigned into PH group (n=279) and non-PH group (n=423). The former group was further divided into mild PH subgroup (n=188) and severe PH subgroup (n=91) based on their systolic pulmonary arterial pressure (SPAP). Body mass index (BMI), type B brain natriuretic peptide (BNP), erythrocyte sedimentation rate (ESR), hematocrit (HCT), C-reactive protein (CRP), albumin (ALB), oxygenation index (OI), D-dimer (D-D), fibrinogen (FIB), lactic acid (LA), first second forced expiratory volume (FEV1) and carbohydrate antigen 125(CA125) were compared between the PH and non-PH groups and between the mild PH and severe PH subgroups. SPSS statistics 18.0 was used to analyze the data. Student′s t test or Chi-square test was employed for the comparison between groups. Pearson correlation analysis was used for the influencing factors for SPAP, and multivariate logistic regression analysis for risk factors. Results Compared with the non-PH patients, the PH patients had significantly lower FEV1/predictive value [(46.4±16.5)% vs (67.6±15.4)%] and OI [(226.7±56.9) vs (352.0±49.9)mmHg], and increased BNP [(575.9±53.2) vs (297.8±84.8)pg/ml], CA125 [(39.9±14.5) vs (15.8±12.2)U/L] and SPAP [(59.2±16.3) vs (30.4±9.1)mmHg](all P<0.05). The ratio of FEV1/predictive value [(37.4±16.7)% vs (59.8±14.1)%] and OI [(156.0±80.5) vs (267.7±98.9)mmHg] were obviously higher, while the levels of BNP [(698.0±125.6) vs (495.9±118.2)pg/ml], D-D [(2.9±1.2) vs (1.3±1.2)mg/L], FIB [(4.9±1.4) vs (3.7±1.5) g/L], LA [(3.5±1.8) vs (1.8±1.1)mmol/L], CA125 [(52.8±38.2) vs (32.9±17.5)U/L], and SPAP[(68.3±16.1) vs (55.2±14.3)mmHg] were elevated in the severe PH group than the mild PH group (all P<0.05). Pearson correlation analysis showed that SPAP was negatively correlated with OI (r=-0.459, P=0.021) and FEV1/predictive value (r=-0.442, P=0.035), and positively correlated with BNP (r=0.507, P=0.012), CA125 (r=0.375, P=0.048) and D-D (r=0.401, P=0.030). Multivariate logistic regression analysis indicated that BNP, CA125, D-D, FEV1/ predictive value and OI were risk factors for PH. Conclusion PH is a common complication of COPD. The detection of BNP, CA125, D-D, FEV1/predictive value and OI is helpful to its diagnosis and treatment.