Siliceous rocks are widely distributed in FengxianTaibai basin and composed mainly of siliceous ankeriteankeritic siliceous rockssiliceous rocks, characterized by stable and long extension and a close relationship with regional mineralization. Therefore, the survey and study of the genesis of these siliceous rocks help conduct regional prospecting. Based on field observation, microscopic examination, LRM and electron microprobe analysis, the author investigated geochemical characteristics of siliceous rocks in such aspects as major elements, trace elements and rare earth elements. It is shown that concentrations of Fe and Mn in siliceous rocks are high whereas concentrations of K, Na and Ti are low in these rocks. The Fe2O3/FeO ratios are lower than 1, suggesting that they were formed in a relatively reduction condition. The Fe, Ti, Mn and Al concentrations also imply that the depositional environment of siliceous rocks belongs to a continental margin. Pb, Zn and Cu in siliceous rocks are obviously concentrated. The ∑REE values are low (12.10×10-6～40.46×10-6) and the differentiation between LREE and HREE is evident (2.34～8.68). The chondritenormalized REE patterns of siliceous rocks are inclined to the right, and Ce and Eu assume intermediately negativepositive anomalies. The variation of Ce anomalies from siliceous rocks to siliceous ankerite also indicates that the depositional environment changed from reduction to oxidation.