Through studying weathering characteristics of red weathering crusts developed on carbonate rocks from different stratum systems in Guizhou karst region (including western Hunan Province) , and comparing with red weathering crusts developed on other styles of bed rocks in native and ambient areas under the same climatic zone, we draw conclusions as follows: (1) Weathering intensities of red weathering crusts of carbonate rocks are markedly dominated by the components of their acid-insoluble residua, and the more high weathering maturity of acid-insoluble residue is, in general, the more intense weathering degree of red weathering crust is. Owing to different stratum systems having different compositions of acid-insoluble residua, weathering intensities of red weathering crusts based on them are certainly distinct; (2) Further weathering potential of weathering crust falls along with increasing in weathering maturity of acid-insoluble residue of carbonate rock, and consequently it reach weathering equilibrium more easily; (3) At the sharply transitional interface between rock and soil, geochemical indices of acid-insoluble residua bring abrupt change. Therefore, the dissolution of carbonate does not only not retard and stave the decomposition of silicate, but also promotes its fast weathering; (4) Based on acid-insoluble residua of carbonate rocks up to the degree of kaolinization and even weak laterization, weathering crusts have higher weathering beginning points than that of crystalline rocks, and show higher weathering intensities. Consequently, to generally look on weathering crusts of carbonate rocks as a weak weathering style relative to those of basalt and granite, isn’t logical.