Patients received 100×106 cells every 20 day for four injections within 2 months and screened for 7 times. MSCs were injected intravenously along with 300 ml normal saline to the patient at a maximum rate of 2×106 cells/min. Each infusion took approximately 30 minute to be completed. After each injection, patient stayed at hospital for at least 6h as recovery time. Efficacy of MSCs treatment in these patients were evaluated using the following parameters: pulmonary functions test (PFTs) [forced expiratory volume in 1 second (FEV1), Forced vital capacity (FVC), FEV1/FVC], total lung capacity by body plethysmography, single-breath carbon monoxide diffusing capacity (CO diffusion) , exercise performance [6-minute walk test (6MWT)], Borg scale dyspnea assessment (BSDA), COPD Assessment Test (CAT), St. George's Respiratory Questionnaire (SRGQ) and comprehensive safety evaluation.