The efficacy and safety in MAINTENANCE phase will be assessed every 4 weeks up to 20 weeks or until AD relapse dependent on which time point comes first. At each visit (V5, W4±2days; V6, W8±2days; V7, W12±2days; V8,W16±2days;V9,W20±2days), Investigator needs to evaluate Eczema Area, AD Severity, Visual Skin Assessment, and conduct physical examination, vital sign measurement. The questionnaire of QoL needs to be completed by subjects at the end of maintenance phase.