The Sichuan Basin is an area the most representative of purplish sandstones and shales distribution in China, with the Shaximiao formation (J₂s) being the most widely distributed strata.[Objective] The purpose of this article is to improve soil taxonomy in Sichuan Province, and to discuss rationality of the requirement for hue in classification of "L.C. of Purplish Sandstones and Shales" in line with the Chinese Soil Taxonomy.[Method] A total of 19 soil profiles typical of the Shaximiao formation in Sichuan were selected for analysis of soil-forming environment, morphological features and physico-chemical properties. In line with the criteria set in the Keys to the Chinese Soil Taxonomy (3rd edition), diagnostic horizons and characteristics of the soil profiles were determined and attributions of the profiles specified in the Chinese Soil Taxonomy.[Result] The 19 soil profiles could be sorted into 3 orders, 3 suborders, 7 groups and 12 subgroups, and only 7 of them were found in conformity with the requirement for hue of "L.C. of Purplish Sandstones and Shales", accounting for only 43.75% of the purplish soil, which indicates that most of the purplish soil individuals did not meet this hue requirement.[Conclusion] The purplish soils matched 10 subgroups in the soil taxonomy. Compared with the system of soil genesis classification, the soil taxonomy pays more attention to properties of the purplish soil per se in classification. Taking into account the color characteristics of the purplish soil in this study, it is suggested that the hue range of "2.5YR~5YR, dry value of 4~6 and dry chroma of 3~4" be augmented in addition to the original hue requirements of "L.C. of Purplish Sandstones and Shales", then the purplish soil individuals that match this diagnostic feature in visual colorimetry may reach 64.71% in proportion and increase from 0 to 3 in number in the instrumental colorimetry. Since visual colorimetry is more likely to have errors than instrumental colorimetry it is suggested that the Chinese Soil Taxonomy should stipulate the use of a modern, more objective and more accurate color measuring instrument, and on such a basis the color ranges of some diagnostic features need to be redrafted.