Abstract: In three tobacco planting areas of Guizhou, by use of soil exchange with plough layer breaking, the effects of climatic and soil factors on characteristic materials in tobacco leaves were studied by means of two factors variance analysis and multiple linear regression analysis (stepwise method). The results showed that climatic factors had higher contribution rate to contents of secretion of glandular hairs, nicotine, total nitrogen, reducing sugar and total sugar in tobacco leaves compared with soil factors. However, the main factors affecting potassium contents in tobacco leaves were soil factors. In a certain range, rainfall was favorable to the formation of secretion of glandular hairs, the increase of average temperature was favorable to control of nicotine, rainfall was favorable to the increase of total sugar in vigorous growth stages, the increase of sunshine hours was favorable to the increase of reducing sugar in vigorous growth stages, and the increase of sunshine hours was favorable to control of total nitrogen in mature stages. When mineral composition and active potassium contents in soils were similar, there was mutual inhibition competition between total nitrogen contents in soils and potassium contents in tobacco leaves.