Abstract:In this study, 6 278 topsoil samples and 216 samples of main agricultural products were collected in Ningguo City,Anhui Province, and the total and effective selenium contents in the soil and crop samples were determined, and then the spatial distribution characteristics of soil total selenium content and its main influencing factors were analyzed.The results showed that the average contents of total selenium in soils was 0.645 mg/kg, the percentage of selenium-rich grade was 57.45% in sample number and 70.30% in area, respectively. The content of total selenium in soil was mainly determined by the parent materials, and selenium content were significantly higher in the soils derived from the Sinian and lower Cambrian parent materials than those from the other geologic ages. Furthermore, selenium contents were different in soils under different land use types, which were higher in the orchard and forest than those in the dryland and paddy field. Correlation analysis showed that soil selenium content had significant positive correlations with the contents of organic matter and heavy metals (P<0.01) but no correlation with soil pH. The average contents of effective selenium was 0.023 mg/kg in soils, and the average selenium content was 0.065 mg/kg in rice, 0.022 mg/kg in Carya cathayensis and 0.074 mg/kg in tea. The selenium enrichment rate was as high as 24.04% in rice and 54.88% in Carya cathayensis, indicating that the selenium-rich Carya cathayensis has a broad prospect of market development.