With plenty of energy accessing to the distribution networks, traditional single direction power transmission of “source-grid-load” mode is changing. The wide-area measurement system light (WAMS Light) extends dynamic condition monitoring to the low-voltage grid. With the increasing scale of WAMS Light, the volume of high-precision, high-density data provided by phasor measurement unit (PMU Light) is increasing. Straight listing extensive synchronous data is difficult for dispatchers to extract useful information and learn the system status. This paper presents a compositive visualization method based on geographic information system (GIS) for real-time monitoring of synchronized data in distribution networks. In this paper, the primitive is designed to adequately consider the data characteristics of synchronous data applied in the distribution network. The frequency contour layer, the voltage phasor layer, and the non-electricity information layer are displayed and superimposed on GIS. The trend sparklines are presented according to the zoom level of the GIS, helping dispatchers effectively monitor the actual state and variation trend of each measurement just by one glace.