The mercury deposits of Tongren-wanshan region occur in carbonate rocks of Cambrian. There are no igneous rocks in the region. The present paper deals with the main characteristics of the cinnabar in the mercury deposits. According to data of X-rays diffractions and Infrared spectra of the cinna- bar, all of the cinnabars are belonging to a-cinnabar of low-temperature phase of trigonal system. In the deposits three generations of the cinnabar can be recognized. They can he distinguished in the occurrence, crystal habit and content of trace elements of the mineral. The first generation cinnabar occurs as massive xenomorphic-minute granular aggregates in antimory-mercury ore. Content of antimony in the cinnabar arrives at 0.052 wt.%,selenium 0.02 wt.%，Se/T e= 53.The second generation cinnabar that forms medium-coarse tabular crystal, occurs in brecciated, striped and vein mercury ores. The cinnabar contains 0.0007-0.0024 wt. ooSb, 0.16-0.19wt. %Se, Se/Te=780-2800.The third gene- ration cinnabar occurs in quartzdolomite miarolitic cavities. It forms beautiful rhombohedral {1011}interpenetion twins. The cinnabar contains 0.0007-0.0046wt. %Sb, 0.25-0.87wt. %Se, Se/Te=1790-3870. The temperature of homogeneity of the quartz intergrown with cinnabar range from 100℃ to 190℃. Sulfur isotopic compositions of the cinnabar (ds") range from 14.1% to 23.3%.The salinity of the ore forming fluid range from 14. lwt.%.The ores are fine to coarse crystalline with brecciated and miaroli- tic structure. For this reason, we suggest that the cinnabar of the region was deposited from heated vadose brine and has no relationship with magma.