identify geological regions with different nutrient supply capacities，the method of spectral comparison was used to carry out an agrogeological survey and research towards the soils and the corresponding parent rock in Xingcheng．The research indicated that，within the area of Suizhong granite，97. 69% of the soils were found to be brown soil，Suizhong granite and brown soil exhibited a very similar spatial distribution in Xingcheng． After the spectral curves of the two are measured，the absorption peaks are found to be the same，also the variation trend of the spectral curves is generally the same，which could be concluded that brown soil and Suizhong granite have obvious inheritance relationship in the study area． And based on the study of their mineral spectral characteristics，it can be inferred that the mineral compositions of brown soil and Suizhong granite in Xingcheng area have consistent characteristics．