This paper describes a system, named ENVis, that supports nursing activity analysis based on sensor data. For enabling efficient analysis, such a system should have following functions; 1)sensor data and annotation data are linked seamlessly; 2)various visualizations can be handled; 3)sensor and annotation data of different cases can be directly comparable; 4)multiple data can be handled for obtaining tendency. The ENVis realizes these functions by taking MVC structure. in which the model handles sensor and annotation data indistinguishably, the views are implemented as plug-in modules, and the controller has layered playing time control. This paper describes detail of the ENVis implementation and its effectiveness with practical examples of nursing activity analysis.