Abstract：The suitability of main weathering indices has been studied based on 13 weathered basalt blocks with core-shell structure from 7 rock mass sections in the core area of Emeishan basalt. Poor correlation has been observed between 18 chemical weathering indices and the early-stage weathering grade of the Emeishan basalt. The indices that can be used to evaluate mid-late period weathering degree of the Emeishan basalt include Parker’s index, BA1, BA, BA3, BA2, alkali/alumina ratio, alkali/R2O3 ratio, WPI, SA, SF, Kr, silicate/R2O3 ratio, CIW, CIA and LOI, in which, alkali/alumina ratio, alkali/R2O3 ratio and silicate/R2O3 ratio are more reasonable, while A, B and B1 are the worst. Fe2O3 that controls the alkali/R2O3 ratio, SF, Kr and silicate/R2O3 ratio in the initial weathering stage of Emeishan basalt should be regarded as an important factor to evaluate the weathering degree of Emeishan basalt.