This paper reports the discovery of cinnabar during Hg-anomaly inspection in cities and outskirts of eastern China plain areas and describes its mineralogical characteristics. Such problems as the spatial correspondence of Hg anomaly with cinnabar distribution and the correlation between cinnabar amounts and Hg anomaly are also discussed. The research indicates that cinnabar is an important existing form of Hg in Hg-anomaly soil. This discovery has important academic and application significance in the study and evaluation of environmental effects of Hg-anomaly soil.