This paper shows the effectiveness of dynamic changeover of service components for ubiquitous service composition. Although context-aware services are expected in the forthcoming ubiquitous computing era, conventional service coordination techniques are insufficient because of rigid interface designing. To cope with this problem, we have established a flexible service composition framework, where a semantic-level service scenario is translated and its components are dynamically found, selected, and bound. User situations change with time, so service components should be changed in accordance with context change. We propose a new method that reselects and rebinds service components based on context change. Through a performance measurement, we show the effectiveness and practicality of the new method.