The Shewushan gold deposit is the largest laterite-type gold ore deposit in Asia, and authors discover that cherts covered on the top of the red soil in the gold ore deposit, showing a gradual transition relationship with the silicified limestone. The analysis of cherts approves that the SiO2 content is from 96.87% to 97.90%, and that the Si/Al ratio ranges from 92.84 to 287.66 with average value of 173, therefore, the cherts could be classified as pure cherts. Combining with the macro characteristics, the authors regard that cherts probably formed in the Carlin-type gold’s stage of eliminate carbonatization, which are the product of hydrothermal activity.