Objective To evaluate the efficacy and safety of home noninvasive positive pressure ventilation (HNIPPV) in hypercapnic patients with stable severe chronic obstructive pulmonary disease (COPD).Methods Forty four patients (30 males and 14 females,mean age 68.5 years ( range:60 -80) ) were recruited from a total of 106 patients with arterial PaCO2 ≥ 55 mm Hg in Second Hospital Affiliated to Harbin Medical University from January 2009 to December 2010. Their clinical data were collected and analyzed. The patients in the HNIPPV group ( n =20 ) accepted tiotropium bromide,doxofylline tablets and HNIPPV treatment while those in the control group ( n =24) tiotropium bromide,doxofylline tablets and a low-flow inhalation of oxygen.The entire observation period was 6 months.The parameters before and after 6-month follow-up were compared,including lung function test,6-rain walking distance (6MWD),arterial blood gases (PaO2 and PaCO2 ),dyspnea grade,scores of emotional disorders and mean pulmonary artery pressure (mPAP).Results No significant difference existed in the baseline data between the HNIPPV and control groups.The forced expiratory volume in one second ( FEV1 ),forced vital capacity ( FVC),inspiratory capacity ( IC),6MWD,PaO2,PaCO2,dyspnea grade,hospitalization rate,anxiety scores,depression scores and mPAP showed no significant difference between the HNIPPV and control groups before treatment. However,at Month 6,the differences of IC,6MWD,PaO2,PaCO2,dyspnea grade,anxiety scores,depression scores and mPAP in HNIPPV group ( (1.80 ±0.14) L,(266 ±24) m,(62.6 ±4.6) mm Hg,(46.8 ±2.2) mm Hg,(2.2 ±0.5),(6.5 ±2.4),(6.0 ±1.6),(33.8 ±2.4) mm Hg) were statistically significant compared with the control group (( 1.62 ± 0.14) L,(194±23) m,(56.2±3.8) mmHg,(55.6±3.0) mmHg,(3.2±0.6),(10.6±2.8),( 10.2±2.4),(36.6 ±2.4) mmHg) (P values:0.031,0.018,0.025,0.026,0.001,0.013,0.002,0.014respectively).FEV1 and FVC in the HNIPPV group improved slightly but with no statistically significant difference (all P ＞ 0.05 ). Two patients in the control group were taken to hospital because of acute exacerbation.And hospitalization rates increased in the control group. But no statistically significant difference existed between the HNIPPV and control groups ( P ＞ 0.05 ).The tolerance and compliance of HNIPPV in the HNIPPV group were better and the patients in the HNIPPV group had no pulmonary barotraumas.Conclusion HNIPPV plus tiotropium bromide and doxofylline tablets is both effective and safe in the treatment of hypercapnic patient with stable severe COPD.