The objective of this study is to evaluate the safety and tolerability of GSK573719/GW642444 Inhalation Powder 125/25 mcg once-daily. The product will be delivered via the Novel Dry Powder Inhaler (nDPI) over 52 weeks to Japanese subjects with Chronic Obstructive Pulmonary Disease (COPD). This is a multi-centre, open-label study evaluating the safety of GSK573719/GW642444 Inhalation Powder 125/25 mcg. Treatment will be given once-daily in the morning. The target enrolment is approximately 120 subjects at approximately 20 study centres in Japan. The total duration of subject participation will be 54-55 weeks, consisting of a 7-14 day run-in period, 52-week treatment period and 1-week follow-up period. Subjects meeting all of the inclusion criteria and none of the exclusion criteria at screening visit (Visit 1) will enter 7-14 day run-in period. The run-in period is provided for completion of baseline safety evaluations and to obtain baseline measures of COPD status. Cardiovascular medical history/risk factors will be assessed at baseline. The following information will be collected from subjects receiving study medication and recorded in the eCRF: demography (including gender, ethnic origin and date of birth, height, weight), medical history (including duration of COPD and smoking history), COPD exacerbation assessment (documented history of ≥1 COPD exacerbation that required antibiotics/systemic corticosteroids or hospitalization in the past 12 months), concurrent medical conditions, and concomitant medication. At Visit 2, eligible subjects will start to take GSK573719/GW642444 125/25 mcg, and enter the treatment period. This treatment will be delivered via the Novel Dry Powder Inhaler (nDPI) once daily in the morning for 52 weeks. One nDPI will contain 30 doses of study medication. Subjects will be instructed to administer medication once daily in the morning for the duration of the 52-week treatment period. Each subject should be advised to adhere to this dosing regimen throughout the study. There will be a total of 8 study visits including at screening (Visit 1), initiation of treatment (Visit 2), and at 4weeks, 8 weeks, 12 weeks, 24 weeks, 36 weeks, 52 weeks (Visit 3 through Visit 8, respectively). Follow-up (Visit 9) will be conducted by the phone contact approximately 1 week following the completion/withdrawal of treatment period. A subject will be considered to have completed the study upon completion of the last on-treatment visit (Visit 8). At the end of the treatment period, subjects will be prescribed appropriate COPD medication at the investigator's discretion. Primary endpoint is incidence and severity of adverse events. Secondary endpoints are clinical laboratory tests (hematology, clinical chemistry), change from baseline in vital signs (pulse rate and systolic and diastolic pressure), and 12-lead Electrocardiogram (ECG) assessments. And other endpoints are change from baseline in trough Forced Expiratory Volume in One Second (FEV1) and Forced Vital Capacity (FVC), number of puffs of supplemental use of salbutamol, percentage of rescue-free days, percentage of symptom-free days, mean symptom scores, incidence of COPD exacerbations, and COPD device preference questionnaire.