Inclusion criteria:

• Inclusion Criteria for Entry in Run-in Period A pediatric patient already diagnosed as having bronchial asthma who meets all of the following criteria is eligible for the study:
• Male or female patients aged ≥5 and ≤14 years. Enrolment of a female patient of childbearing potential is allowed only if she is tested negative in the pregnancy testing at the start of treatment period and if she agrees to undergo pregnancy testing at the protocol-specified timings and to take contraceptive measures without fail during the study period.
• Written informed consent must be obtained from the legally acceptable representative of the subject.

Consent of the subject him/herself should also be obtained, wherever possible, after giving an explanation in an as easy to understand as possible manner.

• An outpatient who has been treated with ICS (FP 100-200μg/day or equivalent) for at least 4 weeks prior to Visit 1.
• Is suitable, in the investigator's/subinvestigator's judgment, for treatment with GW815SF HFA MDI 25/50μg (administered as 2 inhalations of 25/50μg) bid.
• Able to use a peak flow meter in a correct manner in the investigator's/subinvestigator's judgment.
• Able to use MDI in a correct manner (with the assistance of his/her caregiver as necessary) in the investigator's/subinvestigator's judgment.

Inclusion Criteria for Entry in Treatment Period A subject will be considered eligible for inclusion in the treatment period only if he/she has completed the run-in period and meets the following criterion.

1. Has been able, in the investigator's/subinvestigator's judgment, to make entries in the asthma diary and measure PEF, as directed, during the run-in period.

Exclusion criteria:

• Exclusion Criteria for Entry in Run-in Period

A patient who applies any of the following criteria is not eligible for the study:

• Admitted to the hospital due to asthma exacerbation within 8 weeks prior to Visit 1.
• Used systemic steroid within 4 weeks prior to Visit 1.
• Received antibacterials or antivirals for treatment of upper or lower respiratory tract infection within 2 weeks prior to Visit 1.
• Has a safety problem in participation in the study because of a serious, uncontrolled systemic disease including nervous system disorder.
• Has or is suspected to have deep-seated mycosis or infection to which no effective antibacterial agent is available.
• Has or is suspected to have hypersensitivity to the investigational product, rescue medication or any ingredients of them.
• Is pregnant or lactating, may be pregnant, or plans for pregnancy during the study period.
• Has received the last dose in another clinical study within 2 months prior to this study.
• Is not eligible for the study in the investigator's/subinvestigator's judgment.

Exclusion Criteria for Entry in Treatment Period

A subject who applies to any of the following criteria is not eligible for the study:

1. Admitted to the hospital due to asthma exacerbation during the run-in period.
2. Had upper or lower respiratory tract infection during the 2 weeks just before Visit 2.
3. Used prohibited drugs during the 2 weeks just before Visit 2.
4. Is not eligible for the study in the investigator's/subinvestigator's judgment.